U.S. patent application number 15/841606 was filed with the patent office on 2018-04-19 for transparent screen for 3d display and 3d display system.
This patent application is currently assigned to FUJIFILM Corporation. The applicant listed for this patent is FUJIFILM Corporation. Invention is credited to Nobuhiko ICHIHARA, Daisuke KASHIWAGI, Michio NAGAI, Yukito SAITOH, Akira YAMAMOTO, Yujiro YANAI.
Application Number | 20180107106 15/841606 |
Document ID | / |
Family ID | 57545583 |
Filed Date | 2018-04-19 |
United States Patent
Application |
20180107106 |
Kind Code |
A1 |
ICHIHARA; Nobuhiko ; et
al. |
April 19, 2018 |
TRANSPARENT SCREEN FOR 3D DISPLAY AND 3D DISPLAY SYSTEM
Abstract
A transparent screen for 3D display having excellent
transparency and an excellent viewing angle, and a 3D display
system are provided. The transparent screen for 3D display has a
plurality of dots, each of the dots having wavelength selectivity
and being formed of a liquid crystal material having a cholesteric
structure, in which the cholesteric structure gives a striped
pattern of bright parts and dark parts in a cross-sectional view of
the dot observed by a scanning electron microscope, the dot
includes a portion having a height that increases continuously to
the maximum height in a direction extending from the edge toward
the center of the dot, in the portion, the angle formed by the
normal line to a line that is formed by a first dark part as
counted from the surface of the dot on the opposite side of the
substrate and the surface of the dot is in the range of 70.degree.
to 90.degree., and right-handed circularly polarized light and
left-handed circularly polarized light are reflected by the
plurality of dots.
Inventors: |
ICHIHARA; Nobuhiko;
(Minami-ashigara-shi, JP) ; YANAI; Yujiro;
(Minami-ashigara-shi, JP) ; YAMAMOTO; Akira;
(Minami-ashigara-shi, JP) ; NAGAI; Michio;
(Minami-ashigara-shi, JP) ; KASHIWAGI; Daisuke;
(Minami-ashigara-shi, JP) ; SAITOH; Yukito;
(Minami-ashigara-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FUJIFILM Corporation |
Tokyo |
|
JP |
|
|
Assignee: |
FUJIFILM Corporation
Tokyo
JP
|
Family ID: |
57545583 |
Appl. No.: |
15/841606 |
Filed: |
December 14, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2016/067245 |
Jun 9, 2016 |
|
|
|
15841606 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G03B 35/26 20130101;
G02B 5/26 20130101; G02B 5/24 20130101; G03B 21/62 20130101; G02B
5/3016 20130101; G02B 30/25 20200101; G02F 1/133528 20130101; G02B
5/10 20130101; G03B 21/604 20130101; G02B 5/09 20130101; G03B
21/608 20130101; G02B 5/201 20130101; G02F 2001/133541
20130101 |
International
Class: |
G03B 21/608 20060101
G03B021/608; G02B 5/24 20060101 G02B005/24; G02B 5/09 20060101
G02B005/09; G02F 1/1335 20060101 G02F001/1335 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 15, 2015 |
JP |
2015-120393 |
Claims
1. A transparent screen for 3D display comprising: a plurality of
dots, each of the dots having wavelength selectivity and being
formed of a liquid crystal material having a cholesteric structure,
wherein the cholesteric structure gives a striped pattern of bright
parts and dark parts in a cross-sectional view of the dot observed
by a scanning electron microscope, the dot includes a portion
having a height that increases continuously to the maximum height
in a direction extending from the edge toward the center of the
dot, in the portion, the angle formed by the normal line to a line
that is formed by a first dark part as counted from the surface of
the dot and the surface of the dot is in the range of 70.degree. to
90.degree., and right-handed circularly polarized light and
left-handed circularly polarized light are reflected by the
plurality of dots.
2. The transparent screen for 3D display according to claim 1,
wherein the plurality of dots include dots that reflect
right-handed circularly polarized light and dots that reflect
left-handed circularly polarized light.
3. The transparent screen for 3D display according to claim 1,
further comprising a transparent substrate having the plurality of
dots formed on the surface thereof.
4. The transparent screen for 3D display according to claim 2,
further comprising a transparent substrate having the plurality of
dots formed on the surface thereof.
5. The transparent screen for 3D display according to claim 3,
wherein the dot that reflects the right-handed circularly polarized
light and the dot that reflects the left-handed circularly
polarized light are formed on one surface of the transparent
substrate.
6. The transparent screen for 3D display according to claim 4,
wherein the dot that reflects the right-handed circularly polarized
light and the dot that reflects the left-handed circularly
polarized light are formed on one surface of the transparent
substrate.
7. The transparent screen for 3D display according to claim 3,
wherein the dot that reflects the right-handed circularly polarized
light is formed on one surface of the transparent substrate and the
dot that reflects the left-handed circularly polarized light is
formed on the other surface of the transparent substrate.
8. The transparent screen for 3D display according to claim 4,
wherein the dot that reflects the right-handed circularly polarized
light is formed on one surface of the transparent substrate and the
dot that reflects the left-handed circularly polarized light is
formed on the other surface of the transparent substrate.
9. The transparent screen for 3D display according to claim 3,
wherein a first transparent substrate having the dot that reflects
the right-handed circularly polarized light formed thereon and a
second transparent substrate having the dot that reflects the
left-handed circularly polarized light formed thereon are provided,
and the first transparent substrate having the dot that reflects
the right-handed circularly polarized light formed thereon and the
second transparent substrate having the dot that reflects the
left-handed circularly polarized light formed thereon are
laminated.
10. The transparent screen for 3D display according to claim 4,
wherein a first transparent substrate having the dot that reflects
the right-handed circularly polarized light formed thereon and a
second transparent substrate having the dot that reflects the
left-handed circularly polarized light formed thereon are provided,
and the first transparent substrate having the dot that reflects
the right-handed circularly polarized light formed thereon and the
second transparent substrate having the dot that reflects the
left-handed circularly polarized light formed thereon are
laminated.
11. The transparent screen for 3D display according to claim 1,
which includes dots each having, in a single dot, a region that
reflects the right-handed circularly polarized light and a region
that reflects the left-handed circularly polarized light.
12. The transparent screen for 3D display according to claim 3,
which includes dots each having, in a single dot, a region that
reflects the right-handed circularly polarized light and a region
that reflects the left-handed circularly polarized light.
13. The transparent screen for 3D display according to claim 1,
wherein the plurality of dots include two or more kinds of dots
that reflect light in wavelength regions different from each
other.
14. The transparent screen for 3D display according to claim 1,
wherein a diameter of the dot is 5 to 250 .mu.m.
15. The transparent screen for 3D display according to claim 1,
wherein a distance between dots adjacent to each other is equal to
or larger than the diameter of the dot and equal to or smaller than
850 .mu.M.
16. The transparent screen for 3D display according to claim 1,
wherein the liquid crystal material is a material obtainable by
curing a liquid crystal composition including a liquid crystal
compound, a chiral agent, and a surfactant.
17. A 3D display system comprising: the transparent screen for 3D
display according to claim 1; a projecting device that projects a
video image on the transparent screen for 3D display by using the
right-handed circularly polarized light and the left-handed
circularly polarized light; and glasses including a right-handed
polarizing filter that transmits the right-handed circularly
polarized light and does not transmit the left-handed circularly
polarized light, and a left-handed polarizing filter that transmits
the left-handed circularly polarized light and does not transmit
the right-handed circularly polarized light.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of PCT International
Application No. PCT/JP2016/067245 filed on Jun. 9, 2016, which
claims priority under 35 U.S.C. .sctn. 119(a) to Japanese Patent
Application No. 2015-120393 filed on Jun. 15, 2015. The above
application is hereby expressly incorporated by reference, in its
entirety, into the present application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention relates to a transparent screen for 3D
display and a 3D display system.
2. Description of the Related Art
[0003] In recent years, in order to enhance a realistic sensation
of an image displayed by an image display apparatus, the
development of an apparatus for displaying a three-dimensional (3D)
image with a stereoscopic feeling is underway.
[0004] In particular, for movies or amusement, an apparatus for
displaying a 3D image with a realistic sensation highly enhanced
due to 3D display with a large screen is provided.
[0005] As such a 3D image display apparatus, an image display
system including a projecting device such as a projector and a
screen is generally used, and a time-sharing system (liquid crystal
shutter system) which is an active type, and a linear polarization
system, a circular polarization system, an anaglyph system, and a
wavelength division system which are a passive type are used as
major systems. Among these, the passive type circular polarization
system is widely used in a movie theater or the like because a
weight of 3D glasses can be reduced, less flickering occurs, and
brightness is not changed even in a case of inclining a face.
[0006] In the circular polarization system, irradiation is
performed while an image for a right eye and an image for a left
eye from a projecting device are alternatingly being switched. At
the same time, two kinds of circularly polarizing plates (or
.lamda./4 plates) are switched in accordance with the images, and
the irradiated light is right-handed circularly polarized or
left-handed circularly polarized and is projected on a screen.
[0007] As the screen, a screen which reflects projected video light
without disturbing the circular polarization is used. Therefore,
right-handed circularly polarized light and left-handed circularly
polarized light of the video light reflected on the screen are
respectively incident onto a right eye and a left eye of a viewer
through 3D glasses, each of right and left eyes sees only a
designated frame, and thus a video image is three-dimensionally
viewed.
[0008] In order to express augmented reality, it is proposed that
the screen is made transparent, video images such as a moving image
and a still image are superimposed on a background of the screen,
and the superimposed image is displayed, and is also proposed that
a stereoscopic video image is projected as a video image.
[0009] For example, JP2007-219258A describes that a projection
screen includes a first transparent screen which diffuses and
reflects light having one polarized component, in light including
one polarized component and the other polarized component, and
transmits the other light, and a second screen which is provided on
the back surface side of the first transparent screen and diffuses
and reflects the light transmitted through the first transparent
screen, in which the first transparent screen and the second screen
are disposed to be spaced from each other. It is also described
that by using the second screen having transparency, the whole
projection screen becomes transparent, and by combining the
stereoscopic video image projected on the projection screen and the
background, excellent realistic sensation is achieved.
[0010] Moreover, JP2007-219258A describes that light is selectively
reflected on a polarized-light selective reflection layer formed of
a liquid crystalline composition showing cholesteric
regularity.
SUMMARY OF THE INVENTION
[0011] Generally, reflective type screens can be classified into a
diffusion type, a recursion type, and a mirror reflection type,
depending on the reflection characteristics.
[0012] A diffusion type screen uniformly diffuses and reflects
light that has hit the surface into all directions without
deflection. Therefore, the overall brightness is not so high;
however, the viewing angle can be made wider.
[0013] A recursion type screen reflects light in a direction in
which the light has been projected. Therefore, the brightness
obtainable when viewed from the vicinity of a light source can be
made high.
[0014] A mirror reflection type screen reflects light such that the
incident angle of light is equal to the reflected angle, in the
same manner as in the case of light being reflected by a mirror.
Therefore, the brightness obtainable when viewed at the position of
a reflected angle with respect to the incident angle of light from
a light source, can be made high.
[0015] Such a recursion type or mirror reflection type screen can
have the brightness increased in a particular direction; however,
since the brightness in other directions is lowered, the screen has
a feature that the viewing angle is narrowed.
[0016] Here, in regard to a transparent screen that reflects light
from the front surface side and transmits light from the back
surface side, it is requested to enhance the performance of
transmitting light from the back surface, in addition to an
enhancement in the reflection performance such as an increase in
the brightness of projected light or an increase in the viewing
angle.
[0017] In addition, in regard to the screen for 3D display, in
order to three-dimensionally view a video image, it is necessary to
increase the brightness of the reflected light to a certain degree.
Therefore, in order to view a stereoscopic video image even in a
case where a viewer views the screen from any direction, it is
required to increase the brightness of the reflected light at a
wide viewing angle.
[0018] However, in a case where diffusibility is increased in the
transparent screen for 3D display using a flat layer-shaped
reflection layer as described in JP2007-219258A in order to widen
the viewing angle, there is a problem that the haze value
increases, while transparency is lowered. On the contrary, in a
case where transparency is increased, since the diffusibility is
decreased, there is a problem that the viewing angle is
narrowed.
[0019] In view of such circumstances, it is an object of the
invention to provide a transparent screen for 3D display having
excellent transparency and an excellent viewing angle, and a 3D
display system.
[0020] The inventors of the invention conducted a thorough
investigation on the problems of the prior art technologies, and as
a result, the inventors found that the problems can be solved by
providing a transparent screen for 3D display having a plurality of
dots, each of the dots having wavelength selectivity and being
formed of a liquid crystal material having a cholesteric structure,
in which the cholesteric structure gives a striped pattern of
bright parts and dark parts in a cross-sectional view of the dot
observed by a scanning electron microscope, the dot includes a
portion having a height that increases continuously to the maximum
height in a direction extending from the edge toward the center of
the dot, in the portion, the angle formed by the normal line to a
line that is formed by a first dark part as counted from the
surface of the dot on the opposite side of the substrate and the
surface of the dot is in the range of 70.degree. to 90.degree., and
right-handed circularly polarized light and left-handed circularly
polarized light are reflected by the plurality of dots.
[0021] That is, the inventors found that the above-described object
can be achieved by the following configurations.
[0022] (1) A transparent screen for 3D display comprising: a
plurality of dots, each of the dots having wavelength selectivity
and being formed of a liquid crystal material having a cholesteric
structure, wherein the cholesteric structure gives a striped
pattern of bright parts and dark parts in a cross-sectional view of
the dot observed by a scanning electron microscope, the dot
includes a portion having a height that increases continuously to
the maximum height in a direction extending from the edge toward
the center of the dot, in the portion, the angle formed by the
normal line to a line that is formed by a first dark part as
counted from the surface of the dot and the surface of the dot is
in the range of 70.degree. to 90.degree., and right-handed
circularly polarized light and left-handed circularly polarized
light are reflected by the plurality of dots.
[0023] (2) The transparent screen for 3D display according to (1),
wherein the plurality of dots include dots that reflect
right-handed circularly polarized light and dots that reflect
left-handed circularly polarized light.
[0024] (3) The transparent screen for 3D display according to (1)
or (2), further comprising a transparent substrate having the
plurality of dots formed on the surface thereof.
[0025] (4) The transparent screen for 3D display according to (3),
wherein the dot that reflects the right-handed circularly polarized
light and the dot that reflects the left-handed circularly
polarized light are formed on one surface of the transparent
substrate.
[0026] (5) The transparent screen for 3D display according to (3),
wherein the dot that reflects the right-handed circularly polarized
light is formed on one surface of the transparent substrate and the
dot that reflects the left-handed circularly polarized light is
formed on the other surface of the transparent substrate.
[0027] (6) The transparent screen for 3D display according to (3),
wherein a first transparent substrate having the dot that reflects
the right-handed circularly polarized light formed thereon and a
second transparent substrate having the dot that reflects the
left-handed circularly polarized light formed thereon are provided,
and the first transparent substrate having the dot that reflects
the right-handed circularly polarized light formed thereon and the
second transparent substrate having the dot that reflects the
left-handed circularly polarized light formed thereon are
laminated.
[0028] (7) The transparent screen for 3D display according to any
one of (1) to (6), which includes dots each having, in a single
dot, a region that reflects the right-handed circularly polarized
light and a region that reflects the left-handed circularly
polarized light.
[0029] (8) The transparent screen for 3D display according to any
one of (1) to (7), wherein the plurality of dots include two or
more kinds of dots that reflect light in wavelength regions
different from each other.
[0030] (9) The transparent screen for 3D display according to any
one of (1) to (8), wherein a diameter of the dot is 5 to 250
.mu.m.
[0031] (10) The transparent screen for 3D display according to any
one of (1) to (9), wherein a distance between dots adjacent to each
other is equal to or larger than the diameter of the dot and equal
to or smaller than 850 .mu.m.
[0032] (11) The transparent screen for 3D display according to any
one of (1) to (10), wherein the liquid crystal material is a
material obtainable by curing a liquid crystal composition
including a liquid crystal compound, a chiral agent, and a
surfactant.
[0033] (12) A 3D display system comprising: the transparent screen
for 3D display according to any one of (1) to (11); a projecting
device that projects a video image on the transparent screen for 3D
display by using the right-handed circularly polarized light and
the left-handed circularly polarized light; and glasses including a
right-handed polarizing filter that transmits the right-handed
circularly polarized light and does not transmit the left-handed
circularly polarized light, and a left-handed polarizing filter
that transmits the left-handed circularly polarized light and does
not transmit the right-handed circularly polarized light.
[0034] According to the invention, a transparent screen for 3D
display having excellent transparency and an excellent viewing
angle, and a 3D display system can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1A is a front view conceptually illustrating an example
of a transparent screen for 3D display of the invention.
[0036] FIG. 1B is a cross-sectional view of FIG. 1A cut along the
line B-B.
[0037] FIG. 2 is a schematic cross-sectional view of another
example of the transparent screen for 3D display of the
invention.
[0038] FIG. 3 is a schematic cross-sectional view of another
example of the transparent screen for 3D display of the
invention.
[0039] FIG. 4 is a schematic cross-sectional view of another
example of the transparent screen for 3D display of the
invention.
[0040] FIG. 5 is a schematic cross-sectional view of another
example of the transparent screen for 3D display of the
invention.
[0041] FIG. 6A is schematic front view illustrating an example of
the dot arrangement pattern in the transparent screen for 3D
display illustrated in FIG. 5.
[0042] FIG. 6B is schematic front view illustrating another example
of the dot arrangement pattern in the transparent screen for 3D
display illustrated in FIG. 5.
[0043] FIG. 7 is a schematic cross-sectional view of another
example of the transparent screen of the invention.
[0044] FIG. 8 is a schematic cross-sectional view of another
example of the transparent screen of the invention.
[0045] FIG. 9A is a perspective view conceptually illustrating a 3D
display system of the invention.
[0046] FIG. 9B is a perspective view conceptually illustrating a
configuration of a projecting device.
[0047] FIG. 10 is a view illustrating an image obtained by
observing, by a scanning electron microscope (SEM), a cross-section
of the dots of a transparent screen produced in an Example.
[0048] FIG. 11 is a view conceptually illustrating an example of a
cross-section of a dot.
[0049] FIG. 12 is a schematic cross-sectional view for explaining
the action of dots.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] The transparent screen for 3D display and the 3D display
system of the invention will be explained in detail below. A
numerical value range represented by using "to" in the present
specification means a range including the numerical values
described before and after "to" as the lower limit and the upper
limit, respectively.
[0051] According to the present specification, for example, an
angle such as "45.degree.", "parallel", "perpendicular" or
"orthogonal" means that unless particularly stated otherwise, the
difference between the angle and the exact angle is in the range of
smaller than 5 degrees. The difference between the angle and the
exact angle is preferably smaller than 4 degrees, and more
preferably smaller than 3 degrees.
[0052] According to the present specification, the term
"(meth)acrylate" is used to mean "any one or both of acrylate and
methacrylate".
[0053] According to the present specification, the term "same" is
meant to include an error range that is generally tolerable in the
technical field. According to the present specification, in a case
where it is said "entirety", "all" or "entire surface", the terms
are meant to include error ranges that are generally tolerable in
the technical field, in addition to the case of being 100%, and to
include the cases of, for example, 99% or more, 95% or more, or 90%
or more.
[0054] Visible light is light having wavelengths that can be seen
by human eyes among the electromagnetic waves and indicates light
in the wavelength region of 380 nm to 780 nm. Non-visible light is
light in the wavelength region of shorter than 380 nm or in the
wavelength region of longer than 780 nm.
[0055] Without being limited to this, light in the wavelength
region of 420 nm to 495 nm in the visible light is blue light,
light in the wavelength region of 495 nm to 570 nm is green light,
and light in the wavelength region of 620 nm to 750 nm is red
light.
[0056] In the infrared light, near-infrared light is an
electromagnetic wave in the wavelength region of 780 nm to 2,500
nm. Ultraviolet light is light in the wavelength region of 10 to
380 nm.
[0057] Recursive reflection according to the present specification
means reflection by which incident light is reflected in the
direction of incidence.
[0058] According to the present specification, the term "haze"
means a value measured using a haze meter, NDH-2000, manufactured
by Nippon Denshoku Industries Co., Ltd.
[0059] Theoretically, the haze means a value represented by the
following expression.
(Diffuse transmittance of natural light at 380 to 780 nm)/(diffuse
transmittance of natural light at 380 to 780 nm+direct
transmittance of natural light).times.100%
[0060] The diffuse transmittance is a value that can be calculated
by subtracting the direct transmittance from the omnidirectional
transmittance obtainable by using a spectrophotometer and an
integrating sphere unit. The direct transmittance in the case based
on the value measured using an integrating sphere unit is
transmittance at 0.degree..
[0061] The transparent screen for 3D display of the invention is a
transparent screen for 3D display having a plurality of dots, each
of the dots having wavelength selectivity and being formed of a
liquid crystal material having a cholesteric structure, in which
the cholesteric structure gives a striped pattern of bright parts
and dark parts in a cross-sectional view of the dot observed by a
scanning electron microscope, the dot includes a portion having a
height that increases continuously to the maximum height in a
direction extending from the edge toward the center of the dot, in
the portion, the angle formed by the normal line to a line that is
formed by a first dark part as counted from the surface of the dot
on the opposite side of the substrate and the surface of the dot is
in the range of 70.degree. to 90.degree., and right-handed
circularly polarized light and left-handed circularly polarized
light are reflected by the plurality of dots.
[0062] As described above, for a transparent screen for 3D display
which reflects light from the front surface side and transmits
light from the back surface side, it is requested to enhance the
performance of transmitting light from the back surface, in
addition to an enhancement in the reflection performance such as an
increase in the brightness of projected light or an increase in
diffusibility.
[0063] In addition, in regard to the screen for 3D display, in
order to three-dimensionally view a video image, it is necessary to
increase the brightness of the reflected light to a certain degree.
Therefore, in order to view a stereoscopic video image even in a
case where a viewer views the screen from any direction, it is
required to increase the brightness of the reflected light at a
wide viewing angle.
[0064] However, in regard to a transparent screen for 3D display,
in a case where a portion selectively reflecting light is formed
into a flat layer shape, and diffusibility is increased in order to
widen the viewing angle, there is a problem that the haze value
increases, and transparency is lowered. In contrast, in a case
where transparency is increased, since the diffusibility is
decreased, there is a problem that the viewing angle is
narrowed.
[0065] In this regard, according to the invention, in a transparent
screen which is capable of reflecting video light that is emitted
from a video device such as a projector and enters the front
surface, and transmitting light from the back surface, so that the
video light and the background on the back surface side can be
observed in a superimposed manner, by reflecting light in a
particular wavelength region and transmitting light in other
wavelength regions by using a liquid crystal material having a
cholesteric structure, a liquid crystal material having a
cholesteric structure is formed into a plurality of dot-like
bodies, the 3D display is performed by reflecting right-handed
circularly polarized light and left-handed circularly polarized
light by the plurality of dots, this cholesteric structure of the
dots give a striped pattern of bright parts and dark parts in a
cross-sectional view of a dot observed by scanning electron
microscope and includes a portion having a height that increases
continuously to the maximum height in a direction extending from
the edge toward the center of the dot, and in the portion, the
angle formed by the normal line to a line that is formed by the
first dark part as counted from the surface of the dot on the
opposite side of the substrate and the surface of the dot is in the
range of 70.degree. to 90.degree.. Therefore, light can be
reflected in any direction in addition to mirror reflection, and
the viewing angle can be widened without lowering transparency.
[0066] <Transparent Screen for 3D Display>
[0067] Suitable embodiments of the transparent screen for 3D
display (hereinafter, also referred to as a transparent screen) of
the invention will be explained below with reference to the
drawings. FIG. 1A illustrates a front view of an example of the
transparent screen of the invention, and FIG. 1B illustrates a
cross-sectional view of FIG. 1A cut along the line B-B.
[0068] The drawings presented for the invention are schematic
views, and the relations of the thicknesses of various layers, the
positional relations, and the like do not necessarily coincide with
the actual relations. The same also applies to the following
drawings.
[0069] As illustrated in FIG. 1A and FIG. 1B, a transparent screen
10a has a substrate 12 capable of transmitting light; a plurality
of right-handed polarizing dots 20m and a plurality of left-handed
polarizing dots 20h formed on one principal surface of the
substrate 12; and an overcoat layer 16 formed on the surface on the
side where the right-handed polarizing dots 20m and the left-handed
polarizing dots 20h are formed, so as to embed the right-handed
polarizing dots 20m and the left-handed polarizing dots 20h.
[0070] In FIG. 1A, the overcoat layer 16 is not shown in the
drawing.
[0071] In FIG. 1A, in order to distinguish between the right-handed
polarizing dot 20m and the left-handed polarizing dot 20h, these
dots are shown by adding hatchings different from each other.
[0072] The right-handed polarizing dot 20m is a dot that reflects
the right-handed circularly polarized light and the left-handed
polarizing dot 20h is a dot that reflects the left-handed
circularly polarized light.
[0073] The reflected light of the cholesteric structure of the
liquid crystal material that constitutes the dots is circularly
polarized light. That is, the cholesteric structure of the liquid
crystal material selectively reflects one of right-handed
circularly polarized light or left-handed circularly polarized
light, and transmits the other. The circularly polarized
light-selective reflectivity concerning whether the reflected light
of a cholesteric structure is right-handed circularly polarized
light or left-handed circularly polarized light, depends on the
direction of twist of the spiral of the cholesteric structure.
Selective reflection by a cholesteric liquid crystal occurs such
that in a case in which the direction of twist of the spiral of the
cholesteric liquid crystal is right-handed, right-handed circularly
polarized light is reflected, and in a case in which the direction
of twist of the spiral is left-handed, left-handed circularly
polarized light is reflected.
[0074] Therefore, the right-handed polarizing dot 20m is a dot in
which the direction of twist of the spiral of the cholesteric
liquid crystal is right-handed, and the left-handed polarizing dot
20h is a dot in which the direction of twist of the spiral of the
cholesteric liquid crystal is left-handed.
[0075] As illustrated in FIG. 1A, the right-handed polarizing dot
20m and the left-handed polarizing dot 20h are arranged
alternatingly on the substrate 12 in a horizontal direction in the
drawing, and the same kinds of dots are arranged in a row in the
vertical direction in the drawing.
[0076] Since the right-handed polarizing dot 20m that reflects the
right-handed circularly polarized light and the left-handed
polarizing dot 20h that reflects the left-handed circularly
polarized light are provided, irradiation is performed while an
image for a right eye and an image for a left eye from a projecting
device are alternatingly being switched, the right-handed
circularly polarized light and the left-handed circularly polarized
light can be reflected. Therefore, since a viewer views the video
image projected on the transparent screen through 3D glasses, each
of right and left eyes sees only a designated frame, and thus a
video image is three-dimensionally viewed.
[0077] The right-handed polarizing dot 20m and the left-handed
polarizing dot 20h have the same configuration, except that
directions of polarization of reflected light are different, and
thus in the following description, in a case where it is not
necessary to distinguish between the right-handed polarizing dot
20m and the left-handed polarizing dot 20h, these dots are
collectively explained as dots 20.
[0078] Video light enters through the surface on the side where the
dots 20 are formed. That is, the surface on the side where the dots
20 are formed is a front surface, and the surface on the opposite
side is a back surface.
[0079] As described above, since the dots 20 are formed of a liquid
crystal material having a cholesteric structure having
wavelength-selective reflectivity, the video light that enters
through the surface of the transparent screen 10a on the side where
the plurality of dots 20 are formed is reflected at the surface of
a dot 20. However, since a dot 20 is formed into an approximately
hemispheric shape, the incident angle of the incident video light
changes correspondingly to the various positions on the surface of
the dot 20. Accordingly, the video light is reflected in various
directions, and an effect that the viewing angle is widened can be
manifested.
[0080] By forming a portion reflecting light into a dot shape, a
reflection area ratio in a surface of the substrate is decreased,
and it is possible to increase transparency of the background for
suitably transmitting light.
[0081] Based on the wavelength region of the incident video light,
the dots 20 have wavelength-selective reflectivity of selectively
reflecting light in this wavelength region.
[0082] The cholesteric structure of the liquid crystal material
that constitutes the dots 20 gives a striped pattern of bright
parts and dark parts in a cross-sectional view of a dot observed by
a scanning electron microscope and includes a portion having a
height that increases continuously to the maximum height in a
direction extending from the edge toward the center of the dot, and
in the portion, the angle formed by the normal line to a line that
is formed by a first dark part as counted from the surface of the
dot on the opposite side of the substrate and the surface of the
dot is in the range of 70.degree. to 90.degree..
[0083] More detailed explanation in this regard will be given
later.
[0084] In regard to the transparent screen 10a illustrated in FIG.
1A, arrangement patterns of the right-handed polarizing dot 20m and
the left-handed polarizing dot 20h adopt the pattern in which these
dots are arranged alternatingly on the substrate 12 in a horizontal
direction in the drawing, and the same kinds of dots are arranged
in a row in the vertical direction in the drawing. However, the
invention is not limited to this, and the dots may be arranged
alternatingly or may be arranged randomly in the horizontal
direction and the vertical direction.
[0085] The array densities (the number of dots per unit area) of
the right-handed polarizing dot 20m and the left-handed polarizing
dot 20h may be identical with or different from each other, and
from the viewpoint of suitably performing 3D display, it is
preferable that the array densities of dots are the same.
[0086] In addition, in regard to the transparent screen 10a
illustrated in FIG. 1B, a preferred aspect thereof has an overcoat
layer 16 that is formed so as to cover the dots 20. However, the
invention is not intended to be limited to this, and a
configuration in which the dots 20 are exposed without having the
overcoat layer is also acceptable.
[0087] According to the invention, in a case where the transparent
screen has an overcoat layer 16 as in the case of the transparent
screen 10a illustrated in FIG. 1B, it is preferable from the
viewpoint that transparency can be improved by eliminating surface
unevenness caused by the plurality of dots 20 and flattening a
surface.
[0088] Furthermore, in the case of forming the overcoat layer 16,
from the viewpoint of further enhancing transparency by suppressing
reflection at the interface between the overcoat layer 16 and the
dots 20, it is preferable as the difference between the refractive
index of the overcoat layer 16 and the refractive index of the dots
20 is smaller. The difference in the refractive index is preferably
0.10 or less and more preferably 0.04 or less.
[0089] The transparent screen 10a illustrated in FIG. 1B is
configured such that the right-handed polarizing dot 20m and the
left-handed polarizing dot 20h are formed on one principal surface
of the substrate 12; however, the invention is not limited to this,
and as in the case of a transparent screen 10b illustrated in FIG.
2, the transparent screen 10a may also be configured such that the
plurality of the right-handed polarizing dots 20m are formed on one
principal surface of the substrate 12 and the plurality of the
left-handed polarizing dots 20h are formed on the other principal
surface of the substrate 12.
[0090] The arrangement pattern of the right-handed polarizing dot
20m and the arrangement pattern of the left-handed polarizing dot
20h may be identical with or different from each other.
[0091] Without being limited to the configuration in which the
plurality of the right-handed polarizing dots and the left-handed
polarizing dots are respectively formed on the different principal
surfaces of the substrate, a configuration in which the plurality
of the right-handed polarizing dots and the left-handed polarizing
dots are formed on one principal surface of the substrate 12 and
the plurality of the right-handed polarizing dots and the
left-handed polarizing dots are also formed on the other principal
surface of the substrate 12 is also acceptable.
[0092] The dot arrangement pattern on one principal surface of the
substrate and the dot arrangement pattern on the other principal
surface may be identical with or different from each other.
[0093] The transparent screen 10a illustrated in FIG. 1B is
configured such that the right-handed polarizing dot 20m and the
left-handed polarizing dot 20h are formed on one substrate 12;
however, the invention is not limited to this, and as in the case
of a transparent screen 10c illustrated in FIG. 3, the transparent
screen 10a may also be configured to have two substrate, and
configured such that the plurality of the left-handed polarizing
dots 20h are formed on a first substrate 12a, the plurality of the
right-handed polarizing dots 20m are formed on a second substrate
12b, and the first substrate 12a and the second substrate 12b are
laminated via an adhesive layer 17.
[0094] The example illustrated in the drawing is configured such
that the adhesive layer 17 is formed over the entire surface of the
first substrate 12a and the second substrate 12b, and these
substrates are laminated; however, the invention is not limited to
this, and the example may also be configured such that the adhesive
layer 17 is formed only at edges of the first substrate 12a and the
second substrate 12b, these substrates are laminated, and an air
layer is formed between the first substrate 12a and the second
substrate 12b.
[0095] In FIG. 3, a surface of the first substrate 12a on a side
where the left-handed polarizing dots 20h is not formed and a
surface of the second substrate 12b on a side where the
right-handed polarizing dots 20m are formed are laminated so as to
face each other; however, the invention is not limited to this, and
a surface of the first substrate 12a on a side where the
left-handed polarizing dots 20h are formed and a surface of the
second substrate 12b on a side where the right-handed polarizing
dots 20m is not formed may be laminated so as to face each other, a
surface of the first substrate 12a on a side where the left-handed
polarizing dots 20h are formed and a surface of the second
substrate 12b on a side where the right-handed polarizing dots 20m
are formed may be laminated so as to face each other, or a surface
of the first substrate 12a on a side where the left-handed
polarizing dots 20h is not formed and a surface of the second
substrate 12b on a side where the right-handed polarizing dots 20m
is not formed may be laminated so as to face each other.
[0096] In the example illustrated in FIG. 3, the left-handed
polarizing dots 20h are formed on the first substrate 12a and the
right-handed polarizing dots 20m are formed on the second substrate
12b; however, the invention is not limited to this, and a
configuration in which the left-handed polarizing dots 20h and the
right-handed polarizing dots 20m are formed on the first substrate
12a and the right-handed polarizing dots 20m and the left-handed
polarizing dots 20h are formed on the second substrate 12b is also
acceptable.
[0097] In the configuration having two substrates, by adopting a
configuration in which dots that reflect light with one
polarization direction are formed on one substrate and dots that
reflect light with the other polarization direction are formed on
the other substrate, the transparent screen can also be used as a
transparent screen of a so-called depth-fused 3-D (DFD) system in
which a depth feeling is recognized due to the superimposition of
video images projected on surfaces of the two substrates and the
distance in a thickness direction. In a case of being used as the
DFD system, the surfaces of the two substrates need to be disposed
to be spaced from each other, and a separation distance is
preferably 3 mm to 1,000 mm, more preferably 5 mm to 600 mm, and
particularly preferably 10 mm to 100 mm.
[0098] In the example illustrated in FIG. 3, dots are formed on one
principal surface of each of the first substrate 12a and the second
substrate 12b; however, the invention is not limited to this, and a
configuration in which dots are formed on both surfaces of each of
the first substrate 12a and the second substrate 12b is also
acceptable.
[0099] The first substrate 12a and the second substrate 12b may be
formed of the same material or may be formed of the different
materials. Moreover, the thickness of the first substrate 12a and
the thickness of the second substrate 12b may be identical with or
different from each other.
[0100] In the example illustrated in FIG. 1A, with a configuration
in which a single dot reflects light with one polarization
direction among the right-handed circularly polarized light and the
left-handed circularly polarized light, the right-handed polarizing
dots 20m that reflect the right-handed circularly polarized light
and the left-handed polarizing dots 20h that reflect the
left-handed circularly polarized light are provided and the
right-handed circularly polarized light and the left-handed
circularly polarized light are reflected; however, the invention is
not limited to this, and with a configuration in which a single dot
reflects the right-handed circularly polarized light and the
left-handed circularly polarized light, the right-handed circularly
polarized light and the left-handed circularly polarized light may
be reflected.
[0101] For example, a transparent screen 10d illustrated in FIG. 4
is configured to include, as a plurality of dots, a plurality of
two-layered dots 20W having a right-handed polarizing region 21m
that reflects right-handed circularly polarized light and a
left-handed polarizing region 21h that reflects left-handed
circularly polarized light in a single dot.
[0102] Specifically, the two-layered dot 20W has a configuration in
which two layers, namely, a left-handed polarizing region 21h
formed in a hemispheric shape on the substrate 12 side; and a
right-handed polarizing region 21m laminated on the surface of the
left-handed polarizing region 21h, are laminated in the direction
of the normal line to the substrate 12.
[0103] Such a two-layered dot 20W has a layer that reflects
right-handed circularly polarized light and a layer that reflects
left-handed circularly polarized light, and therefore, the
two-layered dot 20T can reflect right-handed circularly polarized
light and left-handed circularly polarized light of incident video
light with a single dot.
[0104] In the example illustrated in FIG. 4, the two-layered dot
20W is configured to have a left-handed polarizing region 21h and a
right-handed polarizing region 21m laminated in this order from the
substrate 12 side; however, the invention is not intended to be
limited to this, and the two-layered dot 20W may also be configured
to have a right-handed polarizing region 21m and a left-handed
polarizing region 21h laminated in this order.
[0105] The plurality of dots 20 thus formed may be such that all of
the dots 20 reflect light in the same wavelength region as long as
the dots include dots that reflect light with different
polarization directions; however, the invention is not intended to
be limited to this, and a configuration including two or more kinds
of dots that reflect light in wavelength regions different from
each other is also acceptable.
[0106] For example, a transparent screen 10e illustrated in FIG. 5
is configured to include, as a plurality of dots, right-handed
polarizing red dots 20Rm that reflect red light in the wavelength
region of 610 nm to 690 nm and right-handed circularly polarized
light; left-handed polarizing red dots 20Rh that reflect red light
and left-handed circularly polarized light; right-handed polarizing
green dots 20Gm that reflect green light in the wavelength region
of 515 nm to 585 nm and right-handed circularly polarized light;
left-handed polarizing green dots 20Gh that reflect green light and
left-handed circularly polarized light; right-handed polarizing
blue dots 20Bm that reflect blue light in the wavelength region of
420 nm to 480 nm and right-handed circularly polarized light; and
left-handed polarizing blue dots 20Bh that reflect blue light and
left-handed circularly polarized light.
[0107] As such, the transparent screen may be configured to have
two or more kinds of dots that reflect light in wavelength regions
different from each other, and to have dots that reflect
right-handed circularly polarized light and dots that reflect
left-handed circularly polarized light as the dots that reflect
light in various wavelength regions. Therefore, it is possible to
display the video image projected on the transparent screen as a
color image.
[0108] The example illustrated in FIG. 5 is configured to include
dots that reflect the right-handed circularly polarized light
and/or the left-handed circularly polarized light of each of red
light, green light, and blue light; however, the invention is not
intended to be limited to this, and the transparent screen may also
include dots that reflect light in other wavelength regions.
[0109] It is desirable that the dots that reflect the right-handed
circularly polarized light and/or the left-handed circularly
polarized light of each of red light, green light, and blue light
are dots reflecting light in the above-mentioned wavelength
regions, and it is also acceptable that the peak wavelength of the
reflected waves may not be included in the range of the wavelength
regions described above.
[0110] The invention is not limited to a configuration including
dots that reflect the right-handed circularly polarized light
and/or the left-handed circularly polarized light of each of red
light, green light, and blue light, and for example, a
configuration including dots that reflect the right-handed
circularly polarized light and/or the left-handed circularly
polarized light of red light and dots that reflect the right-handed
circularly polarized light and/or the left-handed circularly
polarized light of blue light may be employed, or a configuration
including the dots that reflect the right-handed circularly
polarized light and/or the left-handed circularly polarized light
of each of red light, green light, and blue light, as well as dots
that reflect the right-handed circularly polarized light and/or the
left-handed circularly polarized light of light in another
wavelength region may also be employed.
[0111] Moreover, the example illustrated in FIG. 5 is configured to
have dots that reflect right-handed circularly polarized light and
dots that reflect left-handed circularly polarized light
respectively for the two or more kinds of dots that reflect light
in wavelength regions different from each other; however, the
invention is not limited to this, and the transparent screen may
also be configured, for at least one kind among the dots that
reflect light in wavelength regions different from each other, to
include dots that reflect right-handed circularly polarized light
and dots that reflect left-handed circularly polarized light, and
for the rest, may be configured to include dots reflecting light
that is circularly polarized in any one direction.
[0112] the example illustrated in FIG. 5 is configured to have dots
that reflect the right-handed circularly polarized light and dots
that reflect the left-handed circularly polarized light, in various
wavelength regions; however, the invention is not limited to this,
and a configuration in which the right-handed circularly polarized
light and the left-handed circularly polarized light are reflected
by a single dot, in various wavelength regions.
[0113] For example, a configuration in which a red dot having a
region that reflects right-handed circularly polarized light and a
region that reflects left-handed circularly polarized light for red
light, a green dot having a region that reflects right-handed
circularly polarized light and a region that reflects left-handed
circularly polarized light for green light, and a blue dot having a
region that reflects right-handed circularly polarized light and a
region that reflects left-handed circularly polarized light for
blue light may also be employed.
[0114] Here, in a case in which the transparent screen has dots
that reflect the right-handed circularly polarized light and/or the
left-handed circularly polarized light of light in wavelength
regions different from each other, there are no particular
limitations on the arrangement of the dots, and for example, the
dots may be arranged alternatingly, or may be arranged
randomly.
[0115] For example, in the case where the transparent screen has a
total of six dots of dots that reflect right-handed circularly
polarized light and dots that reflect left-handed circularly
polarized light, for each of the red light, the green light, and
the blue light, dots for each color that reflect light with the
same polarization direction are arranged in sequence in each row in
the vertical direction in the drawing, and dots with the different
polarization directions are arranged alternatingly in the
horizontal direction in the drawing.
[0116] Specifically, as in the case of a transparent screen 10f
illustrated in FIG. 6A, in a first row, the right-handed polarizing
blue dot 20Bm, the right-handed polarizing green dot 20Gm, and the
right-handed polarizing red dots 20Rm are arranged in this order,
in a second row, the left-handed polarizing green dot 20Gh, the
left-handed polarizing red dot 20Rh, and the left-handed polarizing
blue dots 20Bh are arranged in this order, in a third row, the
right-handed polarizing red dots 20Rm, the right-handed polarizing
blue dot 20Bm, and the right-handed polarizing green dot 20Gm are
arranged in this order, and even in a fourth row and so forth, dots
may be arranged in the same manner.
[0117] Alternatively, as in the case of a transparent screen 10g
illustrated in FIG. 6B, a combination in which one right-handed
polarizing blue dot 20Bm, one right-handed polarizing green dot
20Gm, and one right-handed polarizing red dots 20Rm are disposed
such that the interval between one another is equal is designated
as one set, a combination in which one left-handed polarizing blue
dots 20Bh, one left-handed polarizing green dot 20Gh, and one
left-handed polarizing red dot 20Rh are disposed such that the
interval between one another is equal is designated as one set, and
the transparent screen may be configured by arranging a plurality
of the set of dots the reflect the right-handed circularly
polarized light and the set of dots that reflect left-handed
circularly polarized light in the vertical direction and the
horizontal direction in the drawing.
[0118] Furthermore, the various dots may also be configured such
that a single dot reflects light in a plurality of wavelength
regions, and reflects right-handed circularly polarized light and
left-handed circularly polarized light of each of the wavelength
regions. That is, the various dots may be configured to include
dots each having regions that reflect light in wavelength regions
different from each other in a single dot, and having a region that
reflects right-handed circularly polarized light and a region that
reflects left-handed circularly polarized light for each wavelength
region.
[0119] FIG. 7 illustrates a schematic cross-sectional view of
another example of the transparent screen of the invention.
[0120] A transparent screen 10h illustrated in FIG. 7 is configured
to include, as a plurality of dots, a plurality of six-layered dots
20S having a left-handed polarizing red region 21Rh that reflects
red light and left-handed circularly polarized light; a
right-handed polarizing red region 21Rm that reflects red light and
right-handed circularly polarized light; a left-handed polarizing
green region 21Gh that reflects green light and left-handed
circularly polarized light; a right-handed polarizing green region
21Gm that reflects green light and right-handed circularly
polarized light; a left-handed polarizing blue region 21Bh that
reflects blue light and left-handed circularly polarized light; and
a right-handed polarizing blue region 21Bm that reflects blue light
and right-handed circularly polarized light, in a single dot.
[0121] Specifically, the six-layered dot 20S is configured to have
six layers such as a left-handed polarizing red region 21Rh formed
in a hemispheric shape on the substrate 12 side; a right-handed
polarizing red region 21Rm laminated on the surface of the
left-handed polarizing red region 21Rh; a left-handed polarizing
green region 21Gh laminated on the surface of the right-handed
polarizing red region 21Rm; a right-handed polarizing green region
21Gm laminated on the surface of the left-handed polarizing green
region 21Gh; a left-handed polarizing blue region 21Bh laminated on
the surface of the right-handed polarizing green region 21Gm; and a
right-handed polarizing blue region 21Bm laminated on the surface
of the left-handed polarizing blue region 21Bh, laminated in the
direction of the normal line to the substrate 12.
[0122] Since such a six-layered dot 20S has a layer reflecting
right-handed circularly polarized light and a layer reflecting
left-handed circularly polarized light for red light; a layer
reflecting right-handed circularly polarized light and a layer
reflecting left-handed circularly polarized light for green light;
and a layer reflecting right-handed circularly polarized light and
a layer reflecting left-handed circularly polarized light for blue
light, the six-layered dot 20S can reflect right-handed circularly
polarized light and left-handed circularly polarized light of red
light, green light, and blue light of incident video light with a
single dot.
[0123] Next, the materials, shape, and the like of the various
constituent elements of the transparent screen of the invention
will be described in detail.
[0124] [Substrate]
[0125] The substrate that is included in the transparent screen of
the invention functions as a base material for forming dots on the
surface.
[0126] It is preferable that the substrate has a low reflectance
for light at the wavelength at which the dots reflect light, and it
is preferable that the substrate does not include a material that
reflects light at the wavelength at which the dots reflect
light.
[0127] It is also preferable that the substrate is transparent for
the visible light region. The substrate may be colored; however, it
is preferable that the substrate is not colored or is colored to a
low extent. Furthermore, it is preferable that the substrate has a
refractive index of about 1.2 to 2.0, and more preferably about 1.4
to 1.8.
[0128] In a case where it is said in the present specification that
an object is transparent, specifically, the non-polarized light
transmittance (omnidirectional transmittance) at a wavelength of
380 to 780 nm may be 50% or higher, is preferably 70% or higher,
and is more preferably 85% or higher.
[0129] The haze value of the substrate is preferably 30% or lower,
more preferably 0.1% to 25%, and particularly preferably 0.1% to
10%.
[0130] The thickness of the substrate may be selected according to
the applications and is not particularly limited. The thickness may
be about 5 .mu.m to 1,000 .mu.m, and is preferably 10 .mu.m to 250
.mu.M, and more preferably 15 .mu.m to 150 .mu.m.
[0131] The substrate may be single-layered or may be multilayered,
and examples of the substrate in the case of being a single layer
substrate include substrates formed of glass, triacetyl cellulose
(TAC), polyethylene terephthalate (PET), polycarbonate, polyvinyl
chloride, acryl, and a polyolefin. As an example of the substrate
in the case of being a multilayered substrate, a substrate that has
any one of the examples of the substrate in the case of being a
single-layered substrate, as a support, and is provided with
another layer on the surface of the support, may be mentioned.
[0132] For example, an underlayer 18 may be provided between the
support 14 and the dots 20, similarly to the transparent screen 10i
illustrated in FIG. 8. The underlayer is preferably a resin layer,
and is particularly preferably a transparent resin layer. Examples
of the underlayer include a layer for adjusting the surface shape
at the time of forming dots, a layer for improving the adhesive
characteristics to the dots, and an oriented layer for adjusting
the orientation of a polymerizable liquid crystal compound at the
time of forming dots.
[0133] Regarding the underlayer, it is preferable that the
underlayer has a low light reflectance at a wavelength at which the
dots reflect light, and it is preferable that the underlayer does
not include a material that reflects light at the wavelength at
which the dots reflect light. It is also preferable that the
underlayer is transparent. Regarding the underlayer, the refractive
index is preferably about 1.2 to 2.0, and more preferably about 1.4
to 1.8. It is also preferable that the underlayer is formed of a
thermosetting resin or a photocurable resin, which is obtained by
curing a composition that is directly applied on the support
surface and includes a polymerizable compound. Examples of the
polymerizable compound include non-liquid crystal compounds such as
a (meth)acrylate monomer and a urethane monomer.
[0134] The thickness of the underlayer is not particularly limited,
and the thickness is preferably 0.01 to 50 .mu.m, and more
preferably 0.05 to 20 .mu.m.
[0135] [Dots]
[0136] The transparent screen of the invention includes the
plurality of dots formed on the substrate surface. As described
above, regarding the substrate surface where dots are formed, the
dots may be formed on both surfaces of a substrate, or may be
formed on any one surface.
[0137] It is desirable that two or more dots are formed on the
substrate surface. Two or more dots are formed close to each other
on the substrate surface, and a plurality of such dot groups are
formed. At that time, as described above, the plurality of dots may
be arranged regularly in a predetermined pattern, or may be
randomly disposed. The dots may be uniformly arranged over the
entire surface of the substrate, or may be arranged at least in a
partial region of the substrate only.
[0138] Here, the array density of the dots is not particularly
limited, and may be appropriately set according to the
diffusibility (viewing angle), transparency, and the like required
for the transparent screen.
[0139] From the viewpoint that a balance can be achieved between a
wide viewing angle and high transparency, and from the viewpoint of
an appropriate density at which dots can be produced without any
defects such as coalescence or deletion of dots at the time of
production, the area ratio of the dots with respect to the
substrate as viewed in the direction of the normal line to a
principal surface of the substrate is preferably 1.0% to 90.6%,
more preferably 2.0% to 50.0%, and particularly preferably 4.0% to
30.0%.
[0140] In regard to the area ratio of the dots, the area ratio in a
region having a size of 1 mm.times.1 mm was measured in an image
obtainable with a microscope such as a laser microscope, a scanning
electron microscope (SEM) or a transmission electron microscope
(TEM), and the average value at 5 sites was designated as the area
ratio of the dots.
[0141] Similarly, from the viewpoint that a balance can be achieved
between a wide viewing angle and high transparency, the pitch
between adjacent dots is preferably equal to or larger than the
diameter of the dot and equal to or smaller than 850 .mu.m, more
preferably 30 to 300 .mu.m, and particularly preferably 50 to 150
.mu.m.
[0142] Furthermore, from the viewpoint described above, adjacent
dots may contact with each other and are preferably spaced from
each other, and a ratio of dots that do not contact with other dots
(non-contact ratio of dots) in all of the dots is preferably 10% or
higher, more preferably 80% or higher, and particularly preferably
90% or higher.
[0143] In a case in which there are a plurality of dots on the
substrate surface, the diameter and shape of the dots may be all
identical, or dots having different diameters and shapes may be
included; however, it is preferable that the diameter and shape are
all identical. For example, dots formed under the same conditions
under the intention of forming dots having the same diameter and
the same shape, are preferred.
[0144] According to the present specification, in a case where the
dots are explained, the explanation is applicable to all the dots
in the transparent screen of the invention; however, it is
acceptable that the transparent screen of the invention that
includes the dots thus explained includes dots that do not apply to
the conditions of the same explanation due to deviations or errors
that are tolerable in the present technical field.
[0145] (Shape of Dots)
[0146] The dots may be circular when viewed in the direction of the
normal line to a principal surface of the substrate (hereinafter,
also referred to as substrate normal line direction). The circular
shape may not be a perfect circle, and an approximately circular
shape is still acceptable. In a case where the term center is used
for a dot, this means the center of this circular shape or the
center of gravity. In a case in which there are a plurality of dots
on the substrate surface, it is desirable that the average shape of
the dots is circular, and some dots having a shape that is not
considered circular may be included.
[0147] The dots are such that the diameter as viewed in the
substrate normal line direction is preferably 5 to 250 .mu.m, more
preferably 10 to 200 .mu.m, and particularly preferably 20 to 120
.mu.m.
[0148] The diameter of a dot can be obtained by using an image
obtainable with a microscope such as a laser microscope, a scanning
electron microscope (SEM) or a transmission electron microscope
(TEM), and measuring the length of a straight line that extends
from an edge (border or boundary line of a dot) to another edge and
passes through the center of the dot. The number of dots and the
distance between dots can also be checked from a microscopic image
obtained with a laser microscope, a scanning electron microscope
(SEM), or a transmission electron microscope (TEM).
[0149] In a case in which the shape of the dot is other than a
circular shape when viewed in the substrate normal line direction,
the diameter of a circle having the same circle area as the
projected area of this dot (equivalent circle diameter) is
designated as the diameter of the dot.
[0150] The dot includes a portion having a height that increases
continuously to the maximum height in a direction extending from
the edge toward the center of the dot. That is, the dot includes an
inclined portion or a curved surface portion having a height
increasing from the edge toward the center of the dot. According to
the present specification, the above-described portion may be
referred to as an inclined portion or a curved surface portion. The
inclined portion or curved surface portion represents a portion
that is surrounded by a portion of the dot surface extending from a
point that starts to increase continuously to a point representing
the maximum height, on the dot surface in a cross-sectional view
that is perpendicular to the principal surface of the substrate; a
straight line that links those points with the substrate by the
minimum distance; and the substrate.
[0151] According to the present specification, in a case where the
term "height" is used for the dot, this means "the minimum distance
from a dot on the surface of the dot on the opposite side of the
substrate, to the surface of the substrate on the side where the
dot is formed". At this time, the surface of the dot may be an
interface with another layer. In a case in which the substrate has
surface unevenness, an extension of the substrate surface at the
edge of the dot is regarded as the surface on the side where the
dot is formed. The maximum height is the maximum value of the
height as described above, and for example, the maximum height is
the minimum distance from the apex of the dot to the surface of the
substrate on the side where the dot is formed. The height of a dot
can be checked from a cross-sectional view of the dot that is
obtained by focal point scanning by means of a laser microscope, or
by using a microscope such as SEM or TEM.
[0152] The inclined portion or curved surface portion may be at the
edge in the direction of a section as viewed from the center of the
dot, or may be at the entirety. For example, in a case where the
dot is circular in shape, the edge corresponds to the
circumference; however, the edge may be the edge in the direction
of a section of the circumference (for example, a part
corresponding to a length of 30% or more, 50% or more, 70% or more,
and 90% or less of the circumference), or the edge may be an edge
in the direction of the entirety of the circumference (90% or more,
95% or more, or 99% or more of the circumference). It is preferable
that the edge of a dot is at the entirety. That is, it is
preferable that the change in the height in the direction extending
from the center of the dot toward the circumference is identical in
all directions. Furthermore, it is preferable that the optical
properties such as recursive reflectivity described below and the
properties explained in a cross-sectional view are also identical
in all directions extending from the center toward the
circumference.
[0153] The inclined portion or curved surface portion may exist at
a certain distance that starts from the edge of the dot (border or
boundary line of the circumference) but does not reach the center;
may extend from the edge of the dot to the center; may exist at a
certain distance that starts from a portion at a certain distance
from the border (boundary line) of the circumference of the dot but
does not reach the center; or may extend from a portion at a
certain distance from the edge of the dot, to the center.
[0154] A structure that includes the above-described inclined
portion or curved surface portion may be, for example, a
hemispherical shape having a flat face on the substrate side, a
shape that has been flattened by cutting the top of this
hemispherical shape approximately in parallel to the substrate
(truncated sphere shape), a conical shape having a face on the
substrate side as the bottom face, or a shape that has been
flattened by cutting the top of this conical shape approximately in
parallel to the substrate (truncated cone shape). Among these,
preferred shapes include a hemispherical shape having a flat face
on the substrate side, a shape that has been flattened by cutting
the top of this hemispherical shape approximately in parallel to
the substrate, and a shape that has been flattened by cutting the
top of a conical shape, which has a face on the substrate side as
the bottom face, approximately in parallel to the substrate. The
hemispherical shape is meant to include a hemispherical shape
having a face including the center of the sphere as a flat face, as
well as any of a spherical segment shape obtainable by arbitrarily
cutting a sphere into two (preferably a spherical segment shape
that does not include the center of the sphere).
[0155] The point on the dot surface that gives the maximum height
of the dot may be the apex of a hemispherical shape or a conical
shape, or may be on the face that has been flattened by cutting
approximately in parallel to the substrate as described above. It
is also preferable that all of the dots on the flattened face give
the maximum height of the dot. It is also preferable that the
center of the dot gives the maximum height.
[0156] The angle (for example, an average value) formed by the
surface of a dot on the opposite side of the substrate and the
substrate (surface of the substrate on the side where the dot is
formed), that is, the contact angle between the substrate and the
dot is preferably 40.degree. or larger, and more preferably
60.degree. or larger. In a case where the contact angle is adjusted
to be in this range, a balance between a wide viewing angle and
high transparency can be achieved.
[0157] The angle can be checked from a cross-sectional view of the
dot that is obtained by focal point scanning by means of a laser
microscope, or by using a microscope such as SEM or TEM; however,
according to the present specification, the angle of the contacting
part between the substrate and the dot surface as measured from a
cross-sectional view of SEM image at a surface that includes the
center of the dot and is perpendicular to the substrate, is
employed.
[0158] As described above, the contact angle between the substrate
and the dot can be adjusted to a desired range by providing an
underlayer between the substrate and the dot.
[0159] (Optical Properties of Dots)
[0160] The dots have wavelength-selective reflectivity. The light
for which the dots exhibit selective reflectivity is not
particularly limited, and for example, the light may be any of
infrared light, visible light, ultraviolet light, and the like. For
example, in a case in which the transparent screen is used as a
screen that displays an image created by video light emitted from a
video device such as projector, and the background on the back
surface side of the transparent screen in a superimposed manner, it
is preferable that the light for which the dots exhibit selective
reflectivity is visible light.
[0161] Alternatively, it is also preferable that the reflection
wavelength is selected according to the wavelength of light that is
emitted from the light source used in combination.
[0162] The dots are formed of a liquid crystal material having a
cholesteric structure. The wavelength of the light for which the
dots exhibit selective reflectivity can be carried out by adjusting
the spiral pitch in the cholesteric structure of the liquid crystal
material that forms the dots as described above. In the liquid
crystal material that forms the dots for the transparent screen of
the invention, since the direction of the spiral axis of the
cholesteric structure is controlled as will be described below, the
incident light is reflected by specular reflection as well as in
various directions.
[0163] The dots may be colored; however, it is preferable that the
dots are not colored, or the dots are colored to a low extent.
Thereby, transparency of the transparent screen can be
enhanced.
[0164] (Cholesteric Structure)
[0165] A cholesteric structure is known to exhibit selective
reflectivity for a particular wavelength. The center wavelength
.lamda. of selective reflection depends on the pitch P of the
spiral structure (=period of spiral) in the cholesteric structure,
and follows the relation of the average refractive index n of the
cholesteric liquid crystal and .lamda.=n.times.P. Therefore, the
selective reflection wavelength can be regulated by regulating this
pitch of the spiral structure. Since the pitch of the cholesteric
structure depends on the type of the chiral agent used together
with a polymerizable liquid crystal compound at the time of forming
the dots, or the concentration of addition of the chiral agent, a
desired pitch can be obtained by adjusting these. In regard to the
adjustment of the pitch, a detailed description is given in Fuji
Film Research & Development, No. 50 (2005), pp. 60 to 63. In
regard to the method for measuring the sense or pitch of a spiral,
the methods described in "Ekisho Kagaku Jikken Nyumon (Introduction
to Experiments in Liquid Crystal Chemistry)", edited by Japanese
Liquid Crystal Society, published by Sigma Shuppan K.K., 2007, p.
46; and "Ekisho Benran (Handbook of Liquid Crystals)", Editorial
Committee for the Handbook of Liquid Crystals, Maruzen, Inc., p.
196, can be used.
[0166] A cholesteric structure gives a striped pattern of bright
parts and dark parts in a cross-sectional view of the dot as
observed by a scanning electron microscope (SEM). Two repeated sets
of the bright part and the dark part (two bright parts and two dark
parts) correspond to one pitch of the spiral. From this, the pitch
can be measured from a SEM cross-sectional view. The normal lines
to the various lines of the striped pattern become the direction of
the spiral axis.
[0167] The half-width .DELTA..lamda. (nm) of the selective
reflection zone (circularly polarized light reflection zone) that
exhibits selective reflection is such that .DELTA..lamda. depends
on the birefringence .DELTA.n and the pitch P of the liquid crystal
compound, and follows the relation of
.DELTA..lamda.=.DELTA.n.times.P. Therefore, control of the width of
the selective reflection zone can be carried out by adjusting
.DELTA.n. The adjustment of .DELTA.n can be carried out by
adjusting the type of the polymerizable liquid crystal compound or
the mixing ratio thereof, or by controlling the temperature at the
time of orientation immobilization. The half-width of the
reflection wavelength zone is adjusted according to the
applications of the transparent screen of the invention, and for
example, the half-width is desirably 50 to 500 nm, and preferably
100 to 300 nm.
[0168] (Cholesteric Structure in Dot)
[0169] Regarding the dot, in a case where the above-mentioned
inclined portion or curved surface portion is checked from a
cross-sectional view observed by a scanning electron microscope
(SEM), the angle (hereinafter, also referred to as an angle of a
dark line) formed by the normal line to a line that is formed by a
first dark part as counted from the surface of the dot on the
opposite side of the substrate and the aforementioned surface is in
the range of 70.degree. to 90.degree.. FIG. 11 illustrates a
schematic view of a cross-section of the dot. In this FIG. 11, the
line formed by a dark part is represented by a bold line. As
illustrated in FIG. 11, the angle .theta..sub.1 formed by the
normal line to line Ld.sub.1 that is formed by the first dark part
and the surface of the dot is 70.degree. to 90.degree.. Here, in a
case where the position at the dot surface in the inclined portion
or the curved surface portion is represented by angle .alpha..sub.1
with respect to a line perpendicular to the substrate surface that
passes through the center of the dot, with the angle .alpha..sub.1
being at the position of 30.degree. and at the position of
60.degree., it is desirable that the angle formed by the direction
of the normal line to line Ld.sub.1 that is formed by the first
dark part as counted from the surface of the dot on the opposite
side of the substrate and the aforementioned surface is in the
range of 70.degree. to 90.degree.. Preferably, it is desirable that
for all of the dots at the inclined portion or curved surface
portion described above, the angle formed by the direction of the
normal line to line that is formed by the first dark part as
counted from the surface of the dot on the opposite side of the
substrate and the aforementioned surface is preferably 70.degree.
or larger and more preferably in the range of 80.degree. to
90.degree.. That is, it is desirable that the angle of the dark
line satisfies the above-mentioned angle in some part of the
inclined portion or the curved surface portion, for example, the
angle of the dark line satisfies the aforementioned angle
intermittently in some part of the inclined portion or the curved
surface portion, and it is preferable to satisfy the aforementioned
angle continuously. In a case where the surface is curved in the
cross-sectional view, the angle formed by the surface means an
angle formed by the tangent line of the surface. This angle is
indicated as an acute angle, and, for example, 70.degree. to
90.degree. means that in a case where the angle formed by the
normal line and the surface is indicated as an angle of 0.degree.
to 180.degree., the range of angle is 70.degree. to 110.degree.. In
regard to the cross-sectional view, it is preferable that all of
the lines formed by up to the second dark part as counted from the
surface of the dot on the opposite side of the substrate are such
that the angle formed by the normal line of the lines, and the
aforementioned surface, is in the range of 70.degree. to
90.degree.; it is more preferable that all of the lines formed by
up to the 3.sup.rd or 4.sup.th dark part as counted from the
surface of the dot on the opposite side of the substrate are such
that the angle formed by the normal line of the lines and the
aforementioned surface is in the range of 70.degree. to 90.degree.;
and it is even more preferable that all of the lines formed by up
to the 5.sup.th to 12.sup.th dark part as counted from the surface
of the dot on the opposite side of the substrate are such that the
angle formed by the normal line of the lines and the aforementioned
surface is in the range of 70.degree. to 90.degree..
[0170] The angle is preferably in the range of 80.degree. to
90.degree., and more preferably in the range of 85.degree. to
90.degree..
[0171] Furthermore, it is preferable that the angle .theta..sub.2
formed by the normal line to line Ld.sub.2 that is formed by the
second dark part as counted from the surface of the dot on the
opposite side of the substrate and the aforementioned surface is in
the range of 70.degree. to 90.degree., and it is preferable that
the angle formed by the normal line of the lines formed by the
3.sup.rd to 20.sup.th dark part and the aforementioned surface is
also in the range of 70.degree. to 90.degree..
[0172] The cross-sectional view provided by SEM shows that at the
surface of the dot in the inclined portion or the curved surface
portion, the spiral axis of the cholesteric structure forms an
angle of 70.degree. or larger or preferably in a range of
80.degree. to 90.degree. with the surface. Due to such a structure,
regarding the light entering into the dot, the light entering in
the direction that forms an angle in the direction of the normal
line to the substrate can be caused to enter at an angle close to
be parallel to the direction of the spiral axis of the cholesteric
structure at the inclined portion or the curved surface portion.
Therefore, the light entering into the dot can be reflected in
various directions. Specifically, since the dot causes specular
reflection of incident light relative to the spiral axis of the
cholesteric structure, as illustrated in FIG. 12, with respect to
light In entering in the direction of the normal line to the
substrate, reflected light Ir that is reflected in the vicinity of
the center of the dot is reflected in parallel to the direction of
the normal line to the substrate. Meanwhile, at a position shifted
from the center of the dot (position at which the spiral axis of
the cholesteric structure is shifted relative to the direction of
the normal line to the substrate), the reflected light Ir is
reflected in a direction that is different from the direction of
the normal line to the substrate. Therefore, the light entering
into the dot can be reflected in various directions, and the
viewing angle can be widened. Since the light Ip that is
transmitted through the dot is transmitted in the same direction as
the incident light In, scattering of the transmitted light is
suppressed, the haze can be lowered, and transparency can be
increased.
[0173] It is also preferable that the light entering in the
direction of the normal line to the substrate can be reflected in
all directions. Particularly, it is preferable that the angle
(half-value angle) at which the brightness becomes half the front
surface brightness (peak brightness) can be set to 35.degree. or
larger, and the transparent screen has high reflectivity.
[0174] At the surface of the dot in the inclined portion or the
curved surface portion, since the spiral axis of the cholesteric
structure and the surface form an angle of 70.degree. or larger or
preferably in a range of 80.degree. to 90.degree., it is preferable
that the angle formed by the direction of the normal line to a line
that is formed by the first dark part as counted from the surface
and the direction of the normal line to the substrate decreases
continuously as the height increases continuously.
[0175] The cross-sectional view is a cross-sectional view in an
arbitrary direction including a portion having a height that
increases continuously to the maximum height in the direction
extending from the edge of the dot toward the center, and
typically, the cross-sectional view is desirably a cross-sectional
view of an arbitrary surface that includes the center of the dot
and is perpendicular to the substrate.
[0176] (Method for Producing Cholesteric Structure)
[0177] A cholesteric structure can be obtained by immobilizing a
cholesteric liquid crystal phase. The structure in which a
cholesteric liquid crystal phase is immobilized may be a structure
in which the orientation of the liquid crystal compound that forms
the cholesteric liquid crystal phase is retained, and typically,
the structure may be a structure in which a polymerizable liquid
crystal compound is brought into an orientation state of the
cholesteric liquid crystal phase and then is polymerized and cured
by ultraviolet irradiation, heating or the like, and a layer
lacking fluidity is formed and simultaneously changed into a state
that is free of any factor causing a change in the orientation
state by an external field or an external force. Meanwhile, in
regard to the structure obtained by immobilizing the cholesteric
liquid crystal phase, it is sufficient in a case where the optical
properties of the cholesteric liquid crystal phase are retained,
and it is acceptable in a case where the liquid crystal compound
has already stopped exhibiting liquid crystal properties. For
example, it is acceptable that the polymerizable liquid crystal
compound is macromolecularized by a curing reaction and thereby has
already lost liquid crystallinity.
[0178] The material used for forming the cholesteric structure may
be a liquid crystal composition including a liquid crystal
compound. The liquid crystal compound is preferably a polymerizable
liquid crystal compound.
[0179] The liquid crystal composition including a polymerizable
liquid crystal compound further includes a surfactant. The liquid
crystal composition may further include a chiral agent and a
polymerization initiator.
[0180] ----Polymerizable Liquid Crystal Compound----
[0181] The polymerizable liquid crystal compound may be a rod-like
liquid crystal compound or a disc-like liquid crystal compound;
however, it is preferable that the polymerizable liquid crystal
compound is a rod-like liquid crystal compound.
[0182] Examples of a rod-like polymerizable liquid crystal compound
that forms a cholesteric liquid crystal layer include a rod-like
nematic liquid crystal compound. As the rod-like nematic liquid
crystal compound, azomethines, azoxys, cyanobiphenyls, cyanophenyl
esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl
esters, cyanophenylcyclohexanes, cyano-substituted
phenylpyrimidines, alkoxy-substituted phenylpyrimidines,
phenyldioxanes, tolanes, and alkenylcyclohexylbenzonitriles are
preferably used. Low molecular weight liquid crystal compounds as
well as polymeric liquid crystal compounds can be used.
[0183] A polymerizable liquid crystal compound can be obtained by
introducing a polymerizable group into a liquid crystal compound.
Examples of the polymerizable group include an unsaturated
polymerizable group, an epoxy group, and an aziridinyl group, and
an unsaturated polymerizable group is preferred, while an
ethylenically unsaturated polymerizable group is particularly
preferred. A polymerizable group can be introduced into a molecule
of a liquid crystal compound by various methods. The number of
polymerizable groups that a polymerizable liquid crystal compound
can have is preferably 1 to 6, and more preferably 1 to 3. Examples
of the polymerizable liquid crystal compound include the compounds
described in Makromol. Chem., Vol. 190, p. 2255 (1989); Advanced
Materials, Vol. 5, p. 107 (1993); U.S. Pat. No. 4,683,327A, U.S.
Pat. No. 5,622,648A, U.S. Pat. No. 5,770,107A, WO95/22586A,
WO95/24455A, WO97/00600A, WO98/23580A, WO98/52905A, JP1989-272551A
(JP-H01-272551A), JP1994-16616A (JP-H06-16616A), JP1995-110469A
(JP-H07-110469A), JP1999-80081A (JP-H11-80081A), and
JP2001-328973A. Two or more kinds of polymerizable liquid crystal
compounds may be used in combination. In a case where two or more
kinds of polymerizable liquid crystal compounds are used in
combination, the orientation temperature can be lowered.
[0184] Specific examples of the polymerizable liquid crystal
compound include compounds represented by General Formulae (1) to
(11).
##STR00001##
[0185] [In Compound (11), X.sup.1 is 2 to 5 (Integer).]
[0186] As a polymerizable liquid crystal compound other than those
described above, cyclic organopolysiloxane compounds having a
cholesteric phase as disclosed in JP1982-165480A (JP-S57-165480A),
and the like can be used. Furthermore, regarding the polymeric
liquid crystal compound described above, a polymer in which a
mesogenic group that exhibits liquid crystallinity has been
introduced into a position at the main chain, a side chain, or both
of the main chain and a side chain; a polymer cholesteric liquid
crystal in which a cholesteryl group has been introduced into a
side chain; the liquid crystalline polymer disclosed in
JP1997-133810A (JP-H09-133810A); the liquid crystalline polymer
disclosed in JP1999-293252A (JP-H11-293252A), and the like can be
used.
[0187] The amount of addition of the polymerizable liquid crystal
compound in the liquid crystal composition is preferably 75% to
99.9% by mass, more preferably 80% to 99% by mass, and particularly
preferably 85% to 90% by mass, with respect to the solid content
mass (mass excluding the solvent) of the liquid crystal
composition.
[0188] ----Surfactant----
[0189] It is desirable that the surfactant is a surfactant in which
by adding a surfactant to the liquid crystal composition that is
used in a case where dots are formed, the polymerizable liquid
crystal compound is horizontally oriented on the air interface side
at the time of forming the dots, and dots having the direction of
the spiral axis controlled as explained above are obtained.
[0190] The surfactant is preferably a compound capable of
functioning as an orientation controlling agent that contributes in
order to obtain a cholesteric structure with planar orientation
stably and rapidly. Examples of the surfactant include
silicone-based surfactants and fluorine-based surfactants, and
fluorine-based surfactants are preferred.
[0191] Specific examples of the surfactant include the compounds
described in paragraphs [0082] to [0090] of JP2014-119605A, the
compounds described in paragraphs [0031] to [0034] of
JP2012-203237A, the compounds listed as examples in paragraphs
[0092] and [0093] of JP2005-99248A, the compounds listed as
examples in paragraphs [0076] to [0078] and paragraphs [0082] to
[0085] of JP2002-129162A, and the fluoro(meth)acrylate-based
polymers described in paragraphs [0018] to [0043] of
JP2007-272185A.
[0192] As the horizontal orientation agent, one kind of agent may
be used singly, or two or more kinds of agents may be used in
combination.
[0193] As the fluorine-based surfactant, a compound represented by
General Formula (I) described in paragraphs [0082] to [0090] of
JP2014-119605A is particularly preferred.
(Hb.sup.11-Sp.sup.11-L.sup.11-Sp.sup.12-L.sup.12).sub.m11-A.sup.11-L.sup-
.13-T.sup.11L.sup.14-A.sup.12-(L.sup.15-Sp.sup.13-L.sup.16-Sp.sup.14-Hb.su-
p.11).sub.n11 General Formula (I)
[0194] In General Formula (I), L.sup.11, L.sup.12, L.sup.13,
L.sup.14, L.sup.15, and L.sup.16 each independently represent a
single bond, --O--, --S--, --CO--, --COO--, --OCO--, --COS--,
--SCO--, --NRCO--, or --CONR-- (wherein R in General Formula (I)
represents a hydrogen atom or an alkyl group having 1 to 6 carbon
atoms). --NRCO-- and --CONR-- have an effect of lowering
solubility. --O--, --S--, --CO--, --COO--, --OCO--, --COS--, or
--SCO-- is more preferable, from the viewpoint of having a tendency
that the haze increases at the time of producing dots, and --O--,
--CO--, --COO--, or --OCO-- is even more preferable, from the
viewpoint of stability of the compound. The alkyl group that can be
adopted by R may be linear or branched. The number of carbon atoms
is more preferably 1 to 3, and examples include a methyl group, an
ethyl group, and an n-propyl group.
[0195] Sp.sup.11, Sp.sup.12, Sp.sup.13, and Sp.sup.14 each
independently represent a single bond or an alkylene group having 1
to 10 carbon atoms, and are each more preferably a single bond or
an alkylene group having 1 to 7 carbon atoms, and even more
preferably a single bond or an alkylene group having 1 to 4 carbon
atoms. However, the hydrogen atoms of the alkylene group may be
substituted by fluorine atoms. The alkylene group may or may not be
branched; however, an unbranched, linear alkylene group is
preferred. From the viewpoint of synthesis, it is preferable that
Sp.sup.11 and Sp.sup.14 are identical, while Sp.sup.12 and
Sp.sup.13 are identical.
[0196] A.sup.11 and A.sup.12 each represent a monovalent to
tetravalent aromatic hydrocarbon group. The number of carbon atoms
of the aromatic hydrocarbon group is preferably 6 to 22, more
preferably 6 to 14, even more preferably 6 to 10, and still more
preferably 6. The aromatic hydrocarbon group represented by
A.sup.11 or A.sup.12 may have a substituent. Examples of such a
substituent include an alkyl group having 1 to 8 carbon atoms, an
alkoxy group, a halogen atom, a cyano group, and an ester group.
Regarding an explanation on these groups and preferred ranges
thereof, reference can be made to the description concerning the
following T. Examples of the substituent for the aromatic
hydrocarbon group represented by A.sup.11 or A.sup.12 include a
methyl group, an ethyl group, a methoxy group, an ethoxy group, a
bromine atom, a chlorine atom, and a cyano group. A molecule having
many perfluoroalkyl moieties in the molecule can orient liquid
crystal molecules even in a case of being added in a small amount,
and since this leads to a decrease in the haze, it is preferable
that A.sup.11 and A.sup.12 are tetravalent so as to have more many
perfluoroalkyl groups in the molecule. From the viewpoint of
synthesis, it is preferable that A.sup.11 and A.sup.12 are
identical.
[0197] It is preferable that T.sup.11 represents a divalent group
represented by
##STR00002## [0198] or a divalent aromatic heterocyclic group
(wherein X included in T.sup.11 represents an alkyl group having 1
to 8 carbon atoms, an alkoxy group, a halogen atom, a cyano group,
or an ester group; and Ya, Yb, Yc, and Yd each independently
represent a hydrogen atom or an alkyl group having 1 to 4 carbon
atoms), and T.sup.11 is more preferably,
[0198] ##STR00003## [0199] and even more preferably,
##STR00004##
[0200] The number of carbon atoms of the alkyl group that can be
adopted by X included in T.sup.11 is 1 to 8, preferably 1 to 5, and
more preferably 1 to 3. The alkyl group may be any of a linear
group, a branched group, and a cyclic group, and the alkyl group is
preferably a linear or branched group. Preferred examples of the
alkyl group include a methyl group, an ethyl group, an n-propyl
group, and an isopropyl group, and among them, a methyl group is
preferred. For the alkyl moiety of the alkoxy group that can be
adopted by X included in T.sup.11, reference can be made to the
explanation and preferred range for the alkyl group that can be
adopted by X included in T.sup.11. Examples of the halogen atom
that can be adopted by X include in T.sup.11 include a fluorine
atom, a chlorine atom, a bromine atom, and an iodine atom, and a
chlorine atom and a bromine atom are preferred. Examples of the
ester group that can be adopted by X included in T.sup.11 include a
group represented by R'COO--. R' may be an alkyl group having 1 to
8 carbon atoms. Regarding the explanation and a preferred range for
the alkyl group that can be adopted by R', reference can be made to
the explanation and preferred range for the alkyl group that can be
adopted by X included in T.sup.11. Specific examples of the ester
include CH.sub.3COO-- and C.sub.2H.sub.5COO--. The alkyl group
having 1 to 4 carbon atoms that can be adopted by Ya, Yb, Yc, and
Yd may be a linear group or a branched group. Examples thereof
include a methyl group, an ethyl group, an n-propyl group, and an
isopropyl group.
[0201] It is preferable that the divalent aromatic heterocyclic
group has a 5-membered, 6-membered, or 7-membered heterocyclic
ring. A 5-membered ring or a 6-membered ring is more preferred, and
a 6-membered ring is most preferred. Preferred examples of the
heteroatom that constitutes the heterocyclic ring include a
nitrogen atom, an oxygen atom, and a sulfur atom. The heterocyclic
ring is preferably an aromatic heterocyclic ring. The aromatic
heterocyclic ring is generally an unsaturated heterocyclic ring. An
unsaturated heterocyclic ring having the largest number of double
bonds is more preferred. Examples of the heterocyclic ring include
a furan ring, a thiophene ring, a pyrrole ring, a pyrroline ring, a
pyrrolidine ring, an oxazole ring, an isoxazole ring, a thiazole
ring, an isothiazole ring, an imidazole ring, an imidazoline ring,
an imidazolidine ring, a pyrazole ring, a pyrazoline ring, a
pyrazolidine ring, a triazole ring, a furazan ring, a tetrazole
ring, a pyran ring, a thiine ring, a pyridine ring, a piperidine
ring, an oxazine ring, a morpholine ring, a thiazine ring, a
pyridazine ring, a pyrimidine ring, a pyrazine ring, a piperazine
ring, and a triazine ring. The divalent heterocyclic group may have
a substituent. Regarding the explanation and preferred ranges for
the examples of the substituent, reference can be made to the
explanation and description related to the substituent that can be
adopted by the monovalent to tetravalent aromatic hydrocarbon of
A.sup.1 and A.sup.2.
[0202] Hb.sup.11 represents a perfluoroalkyl group having 2 to 30
carbon atoms, and Hb.sup.11 is more preferably a perfluoroalkyl
group having 3 to 20 carbon atoms, and even more preferably a
perfluoroalkyl group having 3 to 10 carbon atoms. The
perfluoroalkyl group may be any of a linear group, a branched
group, and a cyclic group; however, the perfluoroalkyl group is
preferably a linear or branched group, and more preferably a linear
group.
[0203] m11 and n11 each independently represent 0 to 3, and
m11+n11.gtoreq.1. At this time, a plurality of the structures
described within the parentheses may be identical with or different
from each other; however, it is preferable that the structures are
identical with each other. m11 and n11 in General Formula (I) are
determined based on the valence of A.sup.11 and A.sup.12, and
preferred ranges thereof are also determined based on the preferred
ranges for the valence of A.sup.11 and A.sup.12.
[0204] o and p included in T.sup.11 each independently represent an
integer of 0 or larger, and in a case where o and p are 2 or
larger, the plurality of X's may be identical with or different
from each other. o included in T.sup.11 is preferably 1 or 2. p
included in T.sup.11 is preferably an integer of 1 to 4, and more
preferably 1 or 2.
[0205] The compound represented by General Formula (I) is such that
the molecular structure may have symmetry, or may not have
symmetry. The term symmetry as used herein means that the molecular
structure corresponds to at least any one of point symmetry, line
symmetry, and rotational symmetry, and the term asymmetry means
that the molecular structure does not correspond to any of point
symmetry, line symmetry, and rotational symmetry.
[0206] The compound represented by General Formula (I) is a
compound in which the perfluoroalkyl group (Hb.sup.11) described
above, linking groups
-(-Sp.sup.11-L.sup.11-Sp.sup.12-L.sup.12)m.sub.11-A.sup.11-L.sup.1-
3- and
-L.sup.14-A.sup.12-(L.sup.15-Sp.sup.13-L.sup.16-Sp.sup.14-)n.sub.11-
-, and T, which isp referably a divalent group having an excluded
volume effect, are combined. It is preferable that the two
perfluoroalkyl group (Hb.sup.11) existing in the molecule are
identical with each other, and it is also preferable that the
linking groups
-(-Sp.sup.11-L.sup.11-Sp.sup.12-L.sup.12)m.sub.11-A.sup.11-L.sup.13-
and
-L.sup.14-A.sup.12-(L.sup.15-Sp.sup.13-L.sup.16-Sp.sup.14-)n.sub.11-
existing in the molecule are also identical with each other. It is
preferable that terminal Hb.sup.11-Sp.sup.11-L.sup.11-Sp.sup.12-
and -Sp.sup.13-L.sup.16-Sp.sup.14-Hb.sup.11 are groups represented
by any of the following general formulae.
(C.sub.aF.sub.2a+1)--(C.sub.bH.sub.2b)--
(C.sub.aF.sub.2a+1)--(C.sub.bH.sub.2b)--O--(C.sub.rH.sub.2r)--
(C.sub.aF.sub.2a+1)--(C.sub.bH.sub.2b)--OCO--(C.sub.rH.sub.2r)--
(C.sub.aF.sub.2a+1)--(C.sub.bH.sub.2b)--OCO--(C.sub.rH.sub.2r)--
[0207] In the above formulae, a is preferably 2 to 30, more
preferably 3 to 20, and even more preferably 3 to 10. b is
preferably 0 to 20, more preferably 0 to 10, and even more
preferably 0 to 5. a+b is 3 to 30. r is preferably 1 to 10, and
more preferably 1 to 4.
[0208] Furthermore, it is preferable that the terminal
Hb.sup.11-Sp.sup.11-L.sup.11-Sp.sup.12-L.sup.12- and
-L.sup.15-Sp.sup.13-L.sup.16-Sp.sup.14-Hb.sup.11 in General Formula
(I) are each a group represented by any of the following general
formulae.
(C.sub.aF.sub.2a+1)--(C.sub.bH.sub.2b)--O--
(C.sub.aF.sub.2a+1)--(C.sub.bH.sub.2b)--OCO--
(C.sub.aF.sub.2a+1)--(C.sub.bH.sub.2b)--O--(C.sub.rH.sub.2r)--O--
(C.sub.aF.sub.2a+1)--(C.sub.bH.sub.2b)--OCO--(C.sub.rH.sub.2r)--OCO--
(C.sub.aF.sub.2a+1)--(C.sub.bH.sub.2b)--OCO--(C.sub.rH.sub.2r)--OCO--
The definitions of a, b, and r in the above formulae are the same
as the definitions given right above.
[0209] The amount of addition of the surfactant in the liquid
crystal composition is preferably 0.01% by mass to 10% by mass,
more preferably 0.01% by mass to 5% by mass, and particularly
preferably 0.02% by mass to 1% by mass, with respect to the total
mass of the polymerizable liquid crystal compound.
[0210] ----Chiral Agent (Optically Active Compound)----
[0211] A chiral agent has a function of creating a spiral structure
of the cholesteric liquid crystal phase. Since chiral compounds
have different directions of twist of the spiral or different
pitches of the spiral created by the compounds, the chiral compound
may be selected according to the purpose.
[0212] There are no particular limitations on the chiral agent, and
known compounds (for example, described in Handbook of Liquid
Crystal Devices, Chapter 3, Section 4-3, Chiral agents for TN and
STN, p. 199, edited by the 142.sup.nd Committee of Japan Society
for the Promotion of Science (1989)), isosorbide, and isomannide
derivatives can be used.
[0213] A chiral agent generally includes an asymmetric carbon atom;
however, an axially asymmetric compound or a plane-asymmetric
compound, which does not include an asymmetric carbon atom, can
also be used as a chiral agent. Examples of the axially asymmetric
compound or plane-asymmetric compound include binaphthyl, helicene,
paracyclophane, and derivatives thereof. The chiral agent may have
a polymerizable group. In a case in which both the chiral agent and
the liquid crystal compound have a polymerizable group, a polymer
having a repeating unit derived from a polymerizable liquid crystal
compound and a repeating unit derived from a chiral agent can be
formed by a polymerization reaction between the polymerizable
chiral agent and the polymerizable liquid crystal compound. In the
aspect, it is preferable that the polymerizable group of the
polymerizable chiral agent is a group of the same kind as the
polymerizable group of the polymerizable liquid crystal compound.
Therefore, it is preferable that the polymerizable group of the
chiral agent is also an unsaturated polymerizable group, an epoxy
group, or an aziridinyl group; more preferably an unsaturated
polymerizable group; and particularly preferably an ethylenically
unsaturated polymerizable group.
[0214] The chiral agent may also be a liquid crystal compound.
[0215] In a case in which the chiral agent has a photoisomerizable
group, it is preferable since a desired pattern of reflection
wavelength corresponding to the emitted light wavelength can be
formed by photo mask irradiation with actinic rays or the like
after application and orientation. The photoisomerizable group is
preferably an isomerization site of a compound exhibiting
photochromic properties, an azo group, an azoxy group, or a
cinnamoyl group. Specific compounds that can be used include the
compounds described in JP2002-80478A, JP2002-80851A,
JP2002-179668A, JP2002-179669A, JP2002-179670A, JP2002-179681A,
JP2002-179682A, JP2002-338575A, JP2002-338668A, JP2003-313189A, and
JP2003-313292A.
[0216] Specific examples of the chiral agent include a compound
represented by Formula (12).
##STR00005##
[0217] In the formula, X represents 2 to 5 (integer).
[0218] The content of the chiral agent in the liquid crystal
composition is preferably 0.01 mol % to 200 mol %, and more
preferably 1 mol % to 30 mol %, of the amount of the polymerizable
liquid crystal compound.
[0219] ----Polymerization Initiator----
[0220] In a case in which a polymerizable compound is included in
the liquid crystal composition, it is preferable that the liquid
crystal composition includes a polymerization initiator. In an
aspect of carrying out a polymerization reaction by ultraviolet
irradiation, the polymerization initiator to be used is preferably
a photopolymerization initiator capable of initiating the
polymerization reaction by ultraviolet irradiation. Examples of the
photopolymerization initiator include .alpha.-carbonyl compounds
(described in U.S. Pat. No. 2,367,661A and U.S. Pat. No.
2,367,670A), acyloin ethers (described in U.S. Pat. No.
2,448,828A), .alpha.-hydrocarbon-substituted aromatic acyloin
compounds (described in U.S. Pat. No. 2,722,512A), polynuclear
quinone compounds (described in U.S. Pat. No. 3,046,127A and U.S.
Pat. No. 2,951,758A), combinations of a triarylimidazole dimer and
p-aminophenyl ketone (described in U.S. Pat. No. 3,549,367A),
acridine and phenazine compounds (described in JP1985-105667A
(JP-S60-105667A) and U.S. Pat. No. 4,239,850A), and oxadiazole
compounds (described in U.S. Pat. No. 4,212,970A).
[0221] The content of the photopolymerization initiator in the
liquid crystal composition is preferably 0.1% to 20% by mass, and
more preferably 0.5% by mass to 12% by mass, with respect to the
content of the polymerizable liquid crystal compound.
[0222] ----Crosslinking Agent----
[0223] The liquid crystal composition may optionally include a
crosslinking agent for the purpose of enhancing the film hardness
after curing and enhancing durability. Regarding the crosslinking
agent, an agent capable of curing by means of ultraviolet
radiation, heat, moisture, or the like can be suitably used.
[0224] The crosslinking agent is not particularly limited and can
be appropriately selected according to the purpose. Examples
include polyfunctional acrylate compounds such as
trimethylolpropane tri(meth)acrylate and pentaerythritol
tri(meth)acrylate; epoxy compounds such as glycidyl (meth)acrylate
and ethylene glycol diglycidyl ether; aziridine compounds such as
2,2-bishydroxymethylbutanol tris [3-(1-aziridinyl) propionate] and
4,4-bis(ethyleneiminocarbonylamino)diphenylmethane; isocyanate
compounds such as hexamethylene diisocyanate and biuret type
isocyanate; polyoxazoline compounds having an oxazoline group in a
side chain; and alkoxysilane compounds such as
vinyltrimethoxysilane and
N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. Furthermore, a
known catalyst can be used according to the reactivity of the
crosslinking agent, and thus productivity can be enhanced in
addition to the enhancement of film hardness and durability. These
may be used singly or in combination of two or more kinds
thereof.
[0225] The content of the crosslinking agent is preferably 3% by
mass to 20% by mass, and more preferably 5% by mass to 15% by mass.
In a case where the content of the crosslinking agent is 3% by mass
or more, an effect of increasing the crosslinking density may be
obtained, and in a case where the content is 20% by mass or less,
stability of the cholesteric liquid crystal layer may be
deteriorated.
[0226] ----Other Additives----
[0227] In the case of using the inkjet method that will be
described below as the method for forming dots, a monofunctional
polymerizable monomer may be used in order to obtain ink physical
properties that are generally required. Examples of the
monofunctional polymerizable monomer include 2-methoxyethyl
acrylate, isobutyl acrylate, isooctyl acrylate, isodecyl acrylate,
and octyl/decyl acrylate.
[0228] The liquid crystal composition may further include, if
necessary, a polymerization inhibitor, an antioxidant, an
ultraviolet absorber, a photostabilizer, a coloring material, and
metal oxide fine particles, to the extent that the optical
performance and the like are not deteriorated.
[0229] It is preferable that the liquid crystal composition is used
as a liquid at the time of forming the dots.
[0230] The liquid crystal composition may include a solvent. The
solvent is not particularly limited and can be appropriately
selected according to the purpose; however, an organic solvent is
preferably used.
[0231] The organic solvent is not particularly limited and can be
appropriately selected according to the purpose. Examples thereof
include ketones such as methyl ethyl ketone and methyl isobutyl
ketone; alkyl halides, amides, sulfoxides, heterocyclic compounds,
hydrocarbons, esters, and ethers. These may be used singly or in
combination of two or more kinds thereof. Among these, in a case
where the environmental burden is taken into consideration, ketones
are particularly preferred. The above-mentioned components such as
the monofunctional polymerizable monomer may also function as the
solvent.
[0232] The liquid crystal composition is applied onto a substrate
and then is cured. Thus, dots are formed. Application of the liquid
crystal composition onto the substrate is preferably carried out by
applying as droplets. In a case where a plurality (usually, a large
number) of dots are applied onto the substrate, printing by using
the liquid crystal composition as an ink may be carried out. The
printing method is not particularly limited, and an inkjet method,
a gravure printing method, a flexographic printing method, and the
like can be used; however, an inkjet method is particularly
preferred. A pattern of dots can also be formed by applying a known
printing technology.
[0233] As illustrated in FIG. 4 to FIG. 7, in the case of a dot
having a plurality of regions that reflect light in wavelength
regions different from each other in a single dot, or in the case
of a dot having a layer reflecting right-handed circularly
polarized light and a region reflecting left-handed circularly
polarized light in a single dot, first, a first layer is formed by
applying as droplets a liquid crystal composition that becomes a
layer on the substrate side by the above-mentioned printing method
and curing the liquid crystal composition, and then a second layer
is formed by applying as droplets a liquid crystal composition that
becomes a second layer over the first layer and curing the liquid
crystal composition. Furthermore, a third layer and so forth are
also formed by the same method. Thereby, a dot having a plurality
of regions having different wavelength regions or directions of
polarization of reflected light can be formed.
[0234] The liquid crystal composition after being applied onto the
substrate is dried or heated as necessary, and then is cured. It is
desirable in a case where the polymerizable liquid crystal compound
in the liquid crystal composition is oriented by the process of
drying or heating. In the case of performing heating, the heating
temperature is preferably 200.degree. C. or lower, and more
preferably 130.degree. C. or lower.
[0235] The liquid crystal compound thus oriented may be further
polymerized. Polymerization may be any of thermal polymerization
and photopolymerization based on light irradiation; however,
photopolymerization is preferred. It is preferable to use
ultraviolet radiation for light irradiation. The irradiation energy
is preferably 20 mJ/cm.sup.2 to 50 J/cm.sup.2, and more preferably
100 mJ/cm.sup.2 to 1,500 mJ/cm.sup.2. In order to accelerate the
photopolymerization reaction, light irradiation may be carried out
under heating conditions or in a nitrogen atmosphere. The
wavelength of ultraviolet radiation radiated is preferably 250 nm
to 430 nm. The polymerization reaction ratio is preferably higher
from the viewpoint of stability, and the polymerization reaction
ratio is preferably 70% or higher, and more preferably 80% or
higher.
[0236] The polymerization reaction ratio can be determined by
determining the consumption ratio of the polymerizable functional
group using an IR absorption spectrum.
[0237] [Overcoat Layer]
[0238] The transparent screen may include an overcoat layer. The
overcoat layer may be provided on the surface side of the substrate
where the dots have been formed, and it is preferable that the
overcoat layer flattens the surface of the transparent screen.
[0239] The overcoat layer is not particularly limited; however, as
described above, it is preferable as the difference in the
refractive index between the overcoat layer and the dots is
smaller, and it is preferable that the difference in the refractive
index is 0.04 or less. Since the refractive index of the dots
formed of a liquid crystal material is about 1.6, it is preferable
that the overcoat layer is a resin layer having a refractive index
of about 1.4 to 1.8. By using an overcoat layer having a refractive
index that is close to the refractive index of the dots, the angle
of light that actually enters into the dot from the normal line
(polar angle) can be made smaller. For example, in a case where
light is caused to enter the transparent screen at a polar angle of
45.degree. using an overcoat layer having a refractive index of
1.6, the polar angle of light that actually enters the dot can be
adjusted to about 27.degree.. Therefore, by using an overcoat
layer, the polar angle of light at which the transparent screen
exhibits recursive reflectivity can be extended, and even for a dot
having a small angle formed by the surface of the dot on the
opposite side of the substrate and the substrate, higher recursive
reflectivity can be obtained in a wider range. The overcoat layer
may also have a function as an antireflection layer, a pressure
sensitive adhesive layer, an adhesive layer, or a hard coat
layer.
[0240] An example of the overcoat layer may be a resin layer
obtainable by applying a composition including a monomer on the
surface side of the substrate where dots have been formed, and then
curing the coating film. The resin is not particularly limited, and
the resin may be selected in consideration of adhesiveness to the
substrate or the liquid crystal material with which the dots are
formed, or the like. For example, a thermoplastic resin, a
thermosetting resin, and an ultraviolet-curable resin can be used.
In view of durability, solvent resistance, and the like, a resin of
the type that is cured by crosslinking is preferred, and
particularly, an ultraviolet-curable resin that can be cured in a
short period of time is preferred. Examples of the monomer that can
be used to form the overcoat layer include ethyl (meth)acrylate,
ethylhexyl (meth)acrylate, styrene, methylstyrene,
N-vinylpyrrolidone, polymethylolpropane tri(meth)acrylate,
hexanediol (meth)acrylate, tripropylene glycol di(meth)acrylate,
diethylene glycol di(meth)acrylate, pentaerythritol
tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate,
1,6-hexanediol di(meth)acrylate, and neopentyl glycol
di(meth)acrylate.
[0241] The thickness of the overcoat layer is not particularly
limited, and may be determined in consideration of the maximum
height of the dot. The thickness may be about 5 .mu.m to 100 .mu.m,
preferably 10 .mu.m to 50 .mu.m, and more preferably 20 .mu.m to 40
.mu.m. The thickness is the distance from the dot-formed surface of
the substrate in the area where there are no dots, to the surface
of the overcoat layer on the opposite surface.
[0242] [Adhesive Layer]
[0243] The transparent screen may include an adhesive layer for
laminating two substrates. It is desirable that the adhesive layer
can adhere two substrates, and has transparency.
[0244] The adhesive layer is not particularly limited; however,
similar to the overcoat layer, it is preferable as the difference
in the refractive index between the adhesive layer and the dots is
smaller.
[0245] As the adhesive layer, known pressure sensitive adhesives
and adhesives can be used.
[0246] For example, the pressure sensitive adhesive represents a
substance in which a ratio (tan .delta.=G''/G') of loss modulus G''
to storage modulus G' measured by dynamic viscoelasticity
measurement device is 0.001 to 1.5, that is, a pressure sensitive
adhesive, a substance which easily creeps, or the like is included.
Examples of the pressure sensitive adhesive include a polyvinyl
alcohol-based pressure sensitive adhesive, but are not limited
thereto.
[0247] The thickness of the adhesive layer is not particularly
limited, and may be determined in consideration of the maximum
height of the dot. The thickness may be about 5 .mu.m to 100 .mu.m,
preferably 10 .mu.m to 50 .mu.m, and more preferably 20 .mu.m to 40
.mu.m. The thickness is the distance from one substrate surface to
the other substrate surface.
[0248] Next, a 3D display system using the transparent screen for
3D display of the invention will be explained with reference to
FIG. 9A and FIG. 9B.
[0249] A 3D display system illustrated in FIG. 9A includes the
transparent screen 10 of the invention described above, a
projecting device 102 that projects a video image on the
transparent screen 10, and 3D glasses 104 in which a viewer
wears.
[0250] The projecting device 102 is a known 3D projector which
alternatingly projects an image for a right eye and an image for a
left eye by light with different polarization directions.
[0251] As an example, as illustrated in FIG. 9B, the projecting
device 102 has a light source 110 for emitting video light while
the image for a right eye and the image for a left eye are
alternately being switched, and a circular polarization unit 112
which is disposed near an emitting port of light from the light
source 110, receives the video light emitted from the light source
110, performs circular polarization on the video light.
[0252] The light source 110 has the same configuration as the
optical systems of the projectors in the related art such as a
liquid crystal display (LCD) system, a digital light processing
(DLP) system, and a liquid crystal on silicon (LCOS) system, except
that irradiation of video light is performed while the image for a
right eye and the image for a left eye are alternatingly being
switched.
[0253] The circular polarization unit 112 has a right-handed
circularly polarizing plate 114 which right-handed circularly
polarizes the video light emitted from the light source and made
incident, on one semicircular region in a circular shape, and a
left-handed circularly polarizing plate 116 which left-handed
circularly polarizes the video light, on the other semicircular
region.
[0254] The circular polarization unit 112 performs circular
polarization on the video light which becomes the image for a right
eye in one direction and performs circular polarization on the
video light which becomes the image for a left eye in the other
direction, by rotating the image for a right eye and the image for
a left eye emitted from the light source 110 in accordance with
switching of these images.
[0255] The configuration of projecting device 102 is not limited
thereto, and for example, a configuration including a light source
(projector) for emitting the video light of the image for a right
eye and a light source (projector) for emitting the video light of
the image for a left eye may be employed.
[0256] The 3D glasses 104 is used in a case where the viewer views
the video image emitted from of projecting device 102 and reflected
on the transparent screen 10, and has a right-eye polarizing filter
106 which transmits circularly polarized light with one direction
to a right eye side and shields circularly polarized light with the
other direction and a left-eye polarizing filter 108 which
transmits circularly polarized light with the other direction to a
left eye side and shields circularly polarized light with the one
direction.
[0257] By viewing the video image reflected on the transparent
screen 10 through the 3D glasses 104, only the video light which
becomes the image for a right eye circularly polarized in the one
direction is incident onto the right eye of the viewer and only the
video light which becomes the image for a left eye circularly
polarized in the other direction is incident onto the left eye of
the viewer. Therefore, each of right and left eyes sees only a
designated frame, and thus the viewer three-dimensionally views a
video image.
[0258] Thus, the transparent screen for 3D display and the 3D
display system of the invention has been explained in detail;
however, the invention is not intended to be limited to the
examples described above. It is obvious that various improvements
and modifications may be made to the extent that the gist of the
invention is maintained.
EXAMPLES
[0259] Features of the invention will be more specifically
explained below by way of Examples. The materials, reagents,
amounts of use, amounts of materials, ratios, treatments,
procedures, and the like disclosed in the following Examples can be
modified as appropriate as long as the gist of the invention is
maintained. Therefore, the scope of the invention should not be
interpreted limitedly by the specific examples described below.
Example 1
[0260] (Production of Underlayer)
[0261] A composition as described below was stirred and dissolved
in a vessel that had been kept warm at 25.degree. C., and thus an
underlayer solution was prepared.
TABLE-US-00001 Underlayer solution (parts by mass) Propylene glycol
monomethyl ether acetate 1,000 Dipentaerythritol hexaacrylate
(manufactured by 15.0 Nippon Kayaku Co., Ltd., trade name: KAYARAD
DPHA) MEGAFAC RS-90 (manufactured by DIC Corporation) 85 IRGACURE
819 (manufactured by BASF SE) 3
[0262] The underlayer solution prepared as described above was
applied on a transparent PET film (polyethylene terephthalate,
manufactured by Toyobo Co., Ltd., COSMOSHINE A4100) having a
thickness of 100 .mu.m using a bar coater at a coating amount of 3
mL/m.sup.2. Subsequently, the substrate was heated so as to obtain
a film surface temperature of 90.degree. C., and the solution was
dried for 120 seconds. Then, the underlayer solution was irradiated
with ultraviolet radiation at a dose of 700 mJ/cm.sup.2 using an
ultraviolet irradiation apparatus in an atmosphere purged with
nitrogen at an oxygen concentration of 100 ppm or less, a
crosslinking reaction was carried out, and an underlayer id formed.
Thus, a substrate A was produced.
[0263] (Formation of Cholesteric Liquid Crystal Dots)
[0264] A composition as described below was stirred and dissolved
in a vessel that had been kept warm at 25.degree. C., and thus a
cholesteric liquid crystal ink solution Gm (liquid crystal
composition) was prepared.
TABLE-US-00002 Cholesteric liquid crystal ink solution Gm (parts by
mass) Methoxyethyl acrylate 145.0 Mixture of rod-like liquid
crystal compounds as described 100.0 below IRGACURE 819
(manufactured by BASF SE) 10.0 Chiral agent A having the following
structure 5.78 Surfactant having the following structure 0.08
[0265] Rod-Like Liquid Crystal Compound
##STR00006##
[0266] The numerical values are expressed in % by mass. R
represents a group that is bonded to oxygen atom.
##STR00007##
[0267] The cholesteric liquid crystal ink solution Gm is a material
that forms dots capable of reflecting light having a center
wavelength of 550 nm. The cholesteric liquid crystal ink solution
Gm is a material that forms dots capable of reflecting right-handed
circularly polarized light. That is, the cholesteric liquid crystal
ink solution Gm is a material for forming right-handed polarizing
green dots.
[0268] A cholesteric liquid crystal ink solution Gh was prepared in
the same manner as in the case of the cholesteric liquid crystal
ink solution Gm, except that the chiral agent was changed to a
chiral agent B that will be described below and the amount of
addition thereof was 10.23 parts by mass.
##STR00008##
[0269] The cholesteric liquid crystal ink solution Gh is a material
for forming left-handed polarizing green dots that reflect
left-handed circularly polarized light having a center wavelength
of 550 nm.
[0270] Each of the cholesteric liquid crystal ink solution Gm and
the cholesteric liquid crystal ink solution Gh prepared as
described above was applied as droplets on the underlayer on the
substrate A produced as described above with an inkjet printer
(DMP-2831, manufactured by Fujifilm Dimatix, Inc.) over the entire
surface of a region having a size of 100 mm.times.100 mm such that
the right-handed polarizing green dot and the left-handed
polarizing green dot were arranged alternatingly and a distance
(pitch) between centers of the adjacent dots became 100 .mu.m, and
the ink solution was dried for 30 seconds at 95.degree. C.
Subsequently, the ink solution was irradiated with ultraviolet
radiation at a dose of 500 mJ/cm.sup.2 at room temperature using an
ultraviolet irradiation apparatus, and was thereby cured to form
dots.
[0271] Hereinafter, a configuration in which right-handed
polarizing dots and left-handed polarizing dots are formed on one
surface of one substrate, as described above, is referred to as a
form A.
[0272] (Evaluation of Dot Shape and Cholesteric Structure)
[0273] Ten dots were randomly selected from among the dots of the
transparent screen obtained as described above, and the shape of
the dots was observed with a laser microscope (manufactured by
Keyence Corporation). The dots had an average diameter of 30 .mu.m
and an average maximum height of 5 .mu.m, and the angle formed at a
contacting portion of both the dot surface at the dot edge and the
underlayer surface (contact angle) was 35 degrees on the average.
The height increased continuously in a direction extending from the
dot edge toward the center.
[0274] One dot positioned at the center of the transparent screen
obtained as described above was cut perpendicularly to the PET
substrate at a plane including the dot center, and the
cross-section was observed with a scanning electron microscope. As
a result, a striped pattern of bright parts and dark parts could be
recognized inside the dot, and a cross-sectional view as
illustrated in FIG. 10 was obtained (the site on the outer side of
the hemispherical shape on the right-hand side of the
cross-sectional view is a burr created at the time of cutting).
[0275] From the cross-sectional view, the angle formed by the
direction of the normal line to a line that was formed by a first
dark part as counted from the surface on the air interface side of
the dot and the surface on the air interface side, was measured,
the angles at the dot edge, between the dot edge and the center,
and at the dot center were 85 degrees, 85 degrees, and 85 degrees,
respectively, and these values were continuously maintained on a
curved surface portion of the dot. In Table 1, the angle is written
as Angle (degrees) formed by normal line direction of dark line of
dot and surface of dot. The angle formed by the direction of the
normal line to a line that was formed by a dark line and the
direction of the normal line to the PET substrate, decreased
continuously from 35 degrees, 18 degrees, to 0 degrees in the order
of positions at the dot edge, between the dot edge and the center,
and at the dot center, respectively.
[0276] (Formation of Overcoat Layer)
[0277] A composition as described below was stirred and dissolved
in a vessel that had been kept warm at 25.degree. C., and thus a
coating liquid for an overcoat layer was prepared.
TABLE-US-00003 Coating liquid for an overcoat layar 1 (parts by
mass) Acetone 100.0 KAYARAD DPCA-30 (manufactured by Nippon Kayaku
Co., 30.0 Ltd.) EA-200 (manufactured by Osaka Gas Chemicals Co.,
Ltd.) 70.0 IRGACURE 819 (manufactured by BASF SE) 3.0
[0278] The coating liquid for an overcoat layer 1 prepared as
described above was applied on the underlayer on which cholesteric
liquid crystal dots had been formed, using a bar coater at a
coating amount of 40 mL/m.sup.2. Subsequently, the substrate was
heated so as to obtain a film surface temperature of 50.degree. C.,
and the coating liquid was dried for 60 seconds. Then, the coating
liquid was irradiated with ultraviolet radiation at a dose of 500
mJ/cm.sup.2 using an ultraviolet irradiation apparatus, and a
crosslinking reaction was carried out to produce an overcoat layer.
Thus, a transparent screen for 3D display as illustrated in FIG. 1B
was obtained.
Example 2
[0279] A transparent screen as illustrated in FIG. 5 was produced
in the same manner as in Example 1, except that the transparent
screen was configured to reflect light in three wavelength regions
different from each other, and to have dots that reflected
right-handed circularly polarized light and dots that reflected
left-handed circularly polarized light as the dots reflecting the
light in various wavelength regions. Moreover, an angle formed by
the normal line direction of the dark line of the dot and the
surface of the dot was measured in the same manner as in Example
1.
[0280] Specifically, a transparent screen was produced by forming
six kinds of dots using a cholesteric liquid crystal ink solution
Gm, a cholesteric liquid crystal ink solution Gh, a cholesteric
liquid crystal ink solution Rm, a cholesteric liquid crystal ink
solution Bm, and a cholesteric liquid crystal ink solution Rh and a
cholesteric liquid crystal ink solution Bh that will be described
below, so as to be arranged in sequence.
[0281] The cholesteric liquid crystal ink solution Rm was prepared
in the same manner as in the case of the cholesteric liquid crystal
ink solution Gm, except that the amount of addition of the chiral
agent A was changed to 4.66 parts by mass.
[0282] The cholesteric liquid crystal ink solution Bm was prepared
in the same manner as in the case of the cholesteric liquid crystal
ink solution Gm, except that the amount of addition of the chiral
agent A was changed to 7.61 parts by mass.
[0283] The cholesteric liquid crystal ink solution Rh was prepared
in the same manner as in the case of the cholesteric liquid crystal
ink solution Gh, except that the amount of addition of the chiral
agent B was changed to 8.62 parts by mass.
[0284] The cholesteric liquid crystal ink solution Bh was prepared
in the same manner as in the case of the cholesteric liquid crystal
ink solution Gh, except that the amount of addition of the chiral
agent B was changed to 12.59 parts by mass.
[0285] The cholesteric liquid crystal ink solutions Rm and Rh are a
material for forming left-handed polarizing red dots that reflect
left-handed circularly polarized light having a center wavelength
of 650 nm, and the cholesteric liquid crystal ink solutions Bm and
Bh are a material for forming left-handed polarizing blue dots that
reflect left-handed circularly polarized light having a center
wavelength of 450 nm.
Example 3
[0286] A transparent screen for 3D display was produced in the same
manner as in Example 1, except that the transparent screen was
configured to include dots having a region that reflected
right-handed circularly polarized light and a region that reflected
left-handed circularly polarized light in a single dot, and an
angle formed by the normal line direction of the dark line of the
dot and the surface of the dot was measured.
[0287] Specifically, the transparent screen for 3D display was
produced by forming the two-layered dot as illustrated in FIG. 4
using the cholesteric liquid crystal ink solution Gm and the
cholesteric liquid crystal ink solution Gh, and an angle formed by
the normal line direction of the dark line of the dot and the
surface of the dot was measured.
[0288] A configuration in which dots having right-handed polarizing
regions and left-handed polarizing regions are formed on one
surface of one substrate, as described above, is referred to as a
form B.
Example 4
[0289] A transparent screen for 3D display as illustrated in FIG. 2
was produced in the same manner as in Example 1, except that
right-handed polarizing dots were formed on one surface of one
substrate and left-handed polarizing dots were formed on the other
surface, and an angle formed by the normal line direction of the
dark line of the dot and the surface of the dot was measured.
[0290] A configuration in which right-handed polarizing dots are
formed on one surface of one substrate and left-handed polarizing
dots are formed on the other surface, as described above, is
referred to as a form C.
Example 5
[0291] A transparent screen for 3D display as illustrated in FIG. 3
was produced in the same manner as in Example 1, except that
right-handed polarizing dots were formed on the first substrate,
left-handed polarizing dots were formed on the second substrate,
and the first substrate and the second substrate were adhered to
each other, and an angle formed by the normal line direction of the
dark line of the dot and the surface of the dot was measured.
[0292] The first substrate and the second substrate were produced
in the same manner as the substrate A.
[0293] As an adhesive layer for adhering the first substrate and
the second substrate to each other, SK-DYNE (manufactured by Soken
Chemical & Engineering Co., Ltd.) was used. The thickness of
the adhesive layer was 20 .mu.m.
[0294] A configuration in which a substrate having right-handed
polarizing dots formed thereon and a substrate having left-handed
polarizing dots formed thereon are adhered to each other, as
described above, is referred to as a form D.
Example 6
[0295] A transparent screen for 3D display was produced in the same
manner as in Example 1, except that the amount of dipentaerythritol
hexaacrylate (DPHA) in the underlayer solution was changed to 99.9
parts by mass, and an angle formed by the normal line direction of
the dark line of the dot and the surface of the dot was
measured.
[0296] The angle formed by the direction of the normal line to a
line that was formed by a first dark part as counted from the
surface on the air interface side of the dot and the surface on the
air interface side was 75 degrees.
Examples 7 to 16
[0297] Transparent screens for 3D display were produced in the same
manner as in Example 1, except that the average diameter of dots
and the distance (pitch) between dots were changed to the values
shown in Table 1, and angles formed by the normal line direction of
the dark line of the dot and the surface of the dot were
measured.
Comparative Example 1
[0298] A transparent screen for 3D display was produced in the same
manner as in Example 1, except that the transparent screen was
configured to have only right-handed polarizing dots.
[0299] A configuration in which a transparent screen has only dots
that reflect one kind of polarized light, as described above, is
referred to as a form E.
Comparative Example 2
[0300] (Production of Underlayer)
[0301] A composition as described below was stirred and dissolved
in a vessel that had been kept warm at 25.degree. C., and thus an
underlayer solution was prepared.
TABLE-US-00004 Underlayer solution (parts by mass) Methyl ethyl
ketone 220 Pentaerythritol triacrylate 100 Leveling agent (BYK361
manufactured by BYK Additives & 0.03 Instruments) LUCIRIN TPO
(manufactured by BASF SE) 4
[0302] The underlayer solution prepared as described above was
applied on a transparent PET (polyethylene terephthalate,
manufactured by Toyobo Co., Ltd., COSMOSHINE A4100) substrate
having a thickness of 100 .mu.m using a bar coater at a coating
amount of 3 mL/m.sup.2. Subsequently, the substrate was heated so
as to obtain a film surface temperature of 80.degree. C., and the
solution was dried for 120 seconds. Thus, an underlayer was
produced.
[0303] (Formation of Cholesteric Liquid Crystal Dots)
[0304] A composition as described below was stirred and dissolved
in a vessel that had been kept warm at 25.degree. C., and thus a
cholesteric liquid crystal ink solution Gm was prepared.
TABLE-US-00005 Cholesteric liquid crystal ink solution Gm (parts by
mass) Methyl isobutyl ketone 250.0 Rod-like liquid crystal compound
having the following structure 100.0 LUCIRIN TPO (manufactured by
BASF SE) 4.0 Chiral agent A having the following structure 5.4
[0305] Rod-Like Liquid Crystal Compound
##STR00009##
[0306] The cholesteric liquid crystal ink solution prepared as
described above was applied as droplets on the underlayer on the
PET produced as described above by a gravure printing method over
the entire surface of a region having a size of 50.times.50 mm such
that the distance between dots was 300 .mu.m and the diameter of
dot was 100 .mu.m, and the ink solution was dried by heating, was
irradiated with ultraviolet radiation, and was crosslinked. Thus,
an optical member was produced.
[0307] The cholesteric liquid crystal ink solution Gm is a material
for forming dots that reflect light having a center wavelength of
550 nm. In addition, the cholesteric liquid crystal ink solution Gm
is a material for forming dots that reflect right-handed circularly
polarized light. That is, the cholesteric liquid crystal ink
solution Gm is a material for forming right-handed polarizing green
dots.
[0308] The cholesteric liquid crystal ink solution Gh was prepared
in the same manner as in the case of the cholesteric liquid crystal
ink solution Gm, except that the chiral agent was changed to a
chiral agent B described above and the amount of addition thereof
was 8.5 parts by mass.
[0309] The cholesteric liquid crystal ink solution Gh is a material
for forming left-handed polarizing green dots that reflect
left-handed circularly polarized light having a center wavelength
of 550 nm.
[0310] An overcoat layer was formed in the same manner as in
Example 1.
[0311] <Evaluation>
[0312] For the transparent screens for 3D display of Examples and
Comparative Examples thus produced, transparency, visibility of 3D
display, viewing angle characteristics, and definition were
evaluated.
[0313] (Evaluation of Transparency)
[0314] Regarding transparency, transmittance was measured using a
haze meter (manufactured by Nippon Denshoku Industries Co., Ltd.),
and transparency was evaluated.
[0315] (Evaluation of Visibility of 3D Display)
[0316] Regarding the evaluation of visibility of 3D display, a
transparent screen was placed in a conventional office environment,
two light sources (EMP 7900 manufactured by Seiko Epson
Corporation) were disposed at a position 1 m away from a front
surface of the transparent screen, and the transparent screen was
irradiated with video light for 3D display by projecting an image
for a right eye and an image for a left eye from each light source.
The screen was observed from a position 3 m away from a front
surface of the screen while changing exposure intensity of the
light source, the exposure intensity necessary for viewing the
video image projected on the transparent screen in a 3D manner was
measured by using an illuminance meter T-10A manufactured by Konica
Minolta, Inc. disposed on a center of the screen, and the
visibility of 3D display was evaluated according to the following
criteria. [0317] A: 1,500 lux or less [0318] B: Greater than 1,500
lux and 3,000 lux or less [0319] C: Greater than 3,000 lux and
8,000 lux or less [0320] D: Greater than 8,000 lux [0321] E: Not
viewed in a 3D manner
[0322] (Evaluation of Viewing Angle Characteristics)
[0323] Viewing angle characteristics are evaluated in the same
manner as the evaluation of visibility of 3D display by observing
from an angle of 45.degree.. The criteria for the evaluation were
also the same.
[0324] (Evaluation of Definition)
[0325] In the evaluation of visibility of 3D display, the exposure
intensity of the light source was set to 2,000 lumens, and a
display image was observed. The definition of the display image was
evaluated according to the following criteria. [0326] A: Favorable
[0327] B: Slightly rough [0328] C: Rough
[0329] The results are presented in Table 1.
TABLE-US-00006 TABLE 1 Angle (degrees) formed Selective reflection
DPHA amount in by normal line direction wavelength underlayer of
dark line of dot and Dot diameter Form 450 nm 550 nm 650 nm (parts
by mass) surface of dot (.mu.m) Example 1 A -- 550 nm -- 15 85 30
Example 2 A 450 nm 550 nm 650 nm 15 85 30 Example 3 B -- 550 nm --
15 80 30 Example 4 C -- 550 nm -- 15 80 30 Example 5 D -- 550 nm --
15 80 30 Example 6 A -- 550 nm -- 99.9 75 30 Example 7 A -- 550 nm
-- 15 85 3 Example 8 A -- 550 nm -- 15 85 5 Example 9 A -- 550 nm
-- 15 85 30 Example 10 A -- 550 nm -- 15 85 240 Example 11 A -- 550
nm -- 15 85 255 Example 12 A -- 550 nm -- 15 85 30 Example 13 A --
550 nm -- 15 85 30 Example 14 A -- 550 nm -- 15 85 30 Example 15 A
-- 550 nm -- 15 85 30 Example 16 A -- 550 nm -- 15 85 30
Comparative E -- 550 nm -- 15 85 30 Example 1 Comparative A -- 550
nm -- 15 65 30 Example 2 Distance Dot diameter/ Haze value between
dots distance between (transparency) Visibility of Viewing angle
(.mu.m) dots (%) 3D display characteristics Definition Example 1
100 30% 0.7 A A A Example 2 100 30% 0.7 A A A Example 3 100 30% 0.7
A A A Example 4 100 30% 0.7 A A A Example 5 100 30% 0.7 A A A
Example 6 100 30% 0.7 B B A Example 7 10 30% 0.7 B A A Example 8 17
30% 0.7 A A A Example 9 100 30% 0.7 A A A Example 10 800 30% 0.7 A
A A Example 11 850 30% 0.7 A A B Example 12 30 100% 5.0 A A A
Example 13 35 86% 2.0 A A A Example 14 100 30% 0.7 A A A Example 15
800 3.8% 0.5 A A A Example 16 850 3.5% 0.5 A A B Comparative 100
30% 0.7 E -- -- Example 1 Comparative 100 30% 0.7 C C A Example
2
[0330] As shown in Table 1, it can be seen that Examples 1 to 16,
which are transparent screens for 3D display of the invention, can
increase all of the transparency and the viewing angle
characteristics compared to Comparative Example 1.
[0331] From a comparison between Example 1 and Example 6, it can be
seen that the angle formed by the dot surface at the dot edge and
the substrate is preferably 70.degree. or larger.
[0332] From a comparison between Example 1 and Example 2, it can be
seen that performances are maintained in a full color as well as a
single color, without impairing the haze, the visibility of 3D
display, the viewing angle characteristics, and the definition.
[0333] From a comparison among Examples 7 to 11, it can be seen
that the diameter of the dot is preferably 5 .mu.m to 250
.mu.m.
[0334] From a comparison among Examples 12 to 16, it can be seen
that the distance (pitch) between the dots adjacent to each other
is preferably 800 .mu.m or less.
Example 21
[0335] Next, a 3D display of the DFD system without using 3D
glasses was attempted as Example 21.
[0336] The first substrate and the second substrate in Example 5
were used, and a transparent screen for 3D display was produced in
the same manner as in Example 5, except that in a state where the
substrates were are parallel to each other, the both substrates
were fixed at a distance between the both substrates of 50 mm.
[0337] Two light sources (EMP 7900 manufactured by Seiko Epson
Corporation) were disposed at a position 1 m away from a front
surface of the transparent screen, and the transparent screen was
irradiated with video light for 3D display of the DFD system by
performing the projection from each light source such that an image
of right-handed circularly polarized light was focused on the first
substrate and an image of left-handed circularly polarized light
was focused on the second substrate.
[0338] As a result, the visibility of 3D display, the viewing angle
characteristics, and the definition equivalent to those of Example
5 using 3D glasses were achieved with naked eyes.
[0339] From the above-described results, the effects of the
invention are obvious.
EXPLANATION OF REFERENCES
[0340] 10a to 10i: transparent screen for 3D display [0341] 12,
12a, 12b: substrate [0342] 14: support [0343] 16: overcoat layer
[0344] 17: adhesive layer [0345] 18: underlayer [0346] 20m:
right-handed polarizing dot [0347] 20h: left-handed polarizing dot
[0348] 20Rm: right-handed polarizing red dot [0349] 20Rh:
left-handed polarizing red dot [0350] 20Gm: right-handed polarizing
green dot [0351] 20Gh: left-handed polarizing green dot [0352]
20Bm: right-handed polarizing blue dot [0353] 20Bh: left-handed
polarizing blue dot [0354] 20W: two-layered dot [0355] 20S:
six-layered dot [0356] 21m: right-handed polarizing region [0357]
21h: left-handed polarizing region [0358] 21Rm: right-handed
polarizing red region [0359] 21Rh: left-handed polarizing red
region [0360] 21Gm: right-handed polarizing green region [0361]
21Gh: left-handed polarizing green region [0362] 21Bm: right-handed
polarizing blue region [0363] 21Bh: left-handed polarizing blue
region [0364] 100: 3D display system [0365] 102: projecting device
[0366] 104: 3D glasses [0367] 106: right-eye polarizing filter
[0368] 108: left-eye polarizing filter [0369] 110: light source
[0370] 112: circularly polarizing unit [0371] 114: right-handed
circularly polarizing plate [0372] 116: left-handed circularly
polarizing plate
* * * * *